◉ top gun training ◉ Top gun training ◉ Top gun training ◉ Top gun training ◉ top gun training

◉ Top gun training ◉ top gun training ◉ top gun training ◉

class sponsored by
PicoScope 7 techniques
by Adam robertson

presented by
T7-AB
◉ top gun training ◉ top gun training ◉ Top gun training ◉ Top gun training ◉ Top gun training ◉ top gun training ◉
PicoScope 7 Techniques
T$%

AD-6018-8v1.0
XXX-xxxx-x

Training for Automotive

Service Professionals
 Notice
Carquest Technical Institute (CTI) does not make any representation, warranty, guarantee, or endorsement of
any of the products, their use, or methods or techniques described in this book or in class. CTI has not, and
expressly disclaims any obligation to independently test any products described in this book or in class.

The reader is expressly advised to consider and use all safety precautions when undertaking the activities
described in this book or in class. In addition, common sense should be exercised to help avoid all potential
hazards.

CTI assumes no responsibility for the activities of the student relating to this book and or this class. CTI makes
no representation or warranties of any kind, including but not limited to, the warranties of fitness for particular
purpose or merchantability, nor for any implied warranties related thereto, or otherwise. CTI will not be liable
for any consequential, special or exemplary damages resulting, in whole or in part, from the students’ use or
reliance upon the information, instructions, warnings, or other matter contained in this book or covered in class.

CTI Mission
Our Mission is to conduct world-class training for professional technicians and automotive repair facility owners
offered through Advance Auto Parts, Carquest Auto Parts and Autopart International stores that will improve their
ability to diagnose and repair today’s vehicles productively and profitably and to create an enjoyable learning
experience while adhering to ASE certification activity standards.

Objectives:

▪ Understand the advantages and features of each generation of PicoScope hardware

▪ Utilize the improved PicoScope 7 software interface
▪ Learn to make the correct oscilloscope settings for specific circuits and test outcomes
▪ Correctly adapt both Pico and aftermarket probes
▪ Identify and adjust advanced functions as featured in Pico 7 software
▪ Apply basic and advanced Pico 7 functions to specific circuit use cases

Carquest Corporation 2023©

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior
written permission of the publisher.
 Pre-Test Questions

1. Reference waveforms in Pico 7 allows us to overlay known good and bad captures in more than one
scope view at the same time.

__________ True __________ False

2. Pico 7 software includes which channel coupling options? (Circle all that apply.)
A. AC
B. DC
C. Frequency counter
D. All the above

3. Pico 7 software math channels can be used to graph the frequency (acceleration/deceleration) of a crank-
shaft position sensor signal to aid in misfire diagnostics.

__________ True __________ False

4. Which of the following automotive Pico interfaces have a built-in arbitrary waveform generator?
A. 4423
B. 4425
C. 4425A
D. 4823
E. All the above

5. PicoScope 7 must be run on a 64 bit system because of security concerns when using the waveform library.

__________ True __________ False

6. Each scope view in Pico 7 is limited to how many channels when using a 2 channel 4225A interface?
A. 8 B. 6
C. 4 D. 2

7. A 20 kilohertz hardware filter is a built-in feature for use in which Pico automotive interfaces?
(Circle all that apply.)
A. 4423 B. 4823
C. 3423 D. 4425
E. 4425A F. 4225

8. The buffer library in Pico 7 is limited to 64 pages maximum.

__________ True __________ False

9. Pico 7’s connect detect feature can be used to verify proper probe connections and can be used with which
of the following probes?
A. X1
B. Current probes
C. Capacitive ignition probes
D. WPS500x pressure transducer
E. All the above

10. The Pico Diagnostic software suite can be used to perform a relative cranking compression test and show
the results in actual psi of pressure for each cylinder of an 8-cylinder engine if an in-cylinder transducer is
utilized on just 1 cylinder during the test.

__________ True __________ False

 Table of Contents
PicoScope Interfaces & Required Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4225 (A), 4425 (A) & 4823 Differences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
New Features – Not Found in Earlier PicoScope Platforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
PicoScope 4823 Automotive Based 8-Channel Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
PicoScope 4225, 4425A, 4425 & 4425A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Adding Two Math Channels to Channel B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4225, 4225A, 4425 & 4425A: Connect Detect Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Pico Operation & Set-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Start-Up Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Common Issue With Some USB Cables & Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Red Dot: Update Reminder Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
PicoScope 7: Information Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
PicoScope Guided Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Time Base Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Sample Rate Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Trigger Selection Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Buffer Library & Capture Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Save File Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
More Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Waveform Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Settings Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Filters & Resolution Enhancement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Channel Coupling Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Introduction to Math Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Reference Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
PicoScope 7: Reference Waveform Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Saving Reference Waveforms in PicoScope 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Advance/Delay Cursor Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Custom Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Typical Testing Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Terminal Adapters/Jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Attenuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
PicoScope 7 Guided Tests Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Serial Decoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Ignition/Sync/COP Capacitive Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Ultrasonic Parking Sensor & Keyless Entry Test Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Types Of Pressure Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Circuit Testers & Load Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Signal Generators & Decade Boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Variable Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Zoom Functionality Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
PicoScope Diagnostic Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Battery Testing: Set-up & Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Relative Cranking Compression Test With Only Battery Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Pico Diagnostics Using a WPS500x Transducer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Compression Results Without the Raw Data Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Relative Cranking Compression Results With Dead Hole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Raw In-Cylinder Compression Signature Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Example: Using Math Channels for the Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Pico Diagnostics: Power Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
NVH: Frequency, Order, Direction & Force (dB and G) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Subaru: Shake in Steering Wheel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Optical Sensor Kit Required for Propshaft Balancing Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Propshaft Balancing Set-Up Wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
 Introduction to PicoScope 7

This class is designed as an introduction to operating PicoScope 7 soft-

ware. Beyond featuring the operation and manipulation of the software,
it also introduces many available testing probes/techniques that will
significantly increase our diagnostic efficiency. We will be introducing
these techniques with the application of real case studies. Even seasoned
Pico 6 users will benefit from this course.

Topics include:

• Differences between the most common automotive PicoScope

interfaces
• Buttonology of the Pico 7 software
• Features of the PicoScope 7 software
• Case studies to apply software functionality and testing techniques
• Testing probes available for PicoScope from Pico and 3rd party
suppliers
• Introduction to the PicoScope Diagnostic software suite

PicoScope Interfaces & Required Software

There are several Pico interfaces available includ- PicoScope Software Recommendation
ing automotive boxes and test/measurement Software icons

systems. This class is based off Pico Technology’s  Proper PicoScope software downloads should include:
automotive systems. Many of the features that we  PicoScope 6
talk about in the automotive software will not work  PicoScope 7 early access and stable versions
properly with some of the other available Pico in-  Pico Diagnostics – variety of automated test procedures
– Battery test
terfaces. In many cases, there are work arounds
– Compression test
and there can be a lot of information found on the – Power contribution test
internet to take some of their other interface boxes – Propshaft/driveline balancing
and get them to integrate with the automotive soft- – NVH (noise vibration and harshness)
ware, but our advice is to stick with the automotive
based interfaces.

Although PicoScope seven is now the software

platform of choice, there are a few slides in this presentation that were still put out in PicoScope 6. There are still
many technicians that choose PicoScope six as their platform of choice. In our opinion, however, PicoScope 7
is a far better program and is going to replace PicoScope 6 completely.

PicoScope 7 software is now stable. At the time of writing this class, users are still allowed to have PicoScope
7 stable, PicoScope 7 early release and all the normal PicoScope 6 software functions (beta and stable)
on the same computer. In our opinion, it is still prudent to download all platforms due to advanced features in
PicoScope 6 that have not yet been imported/tested into PicoScope 7. Go to the Pico automotive scope web-
site: picoauto.com and follow the links for downloads; you will find all the necessary software. Download and
install the software. All four icons should now display on your computer’s desktop screen.

Notice on the desktop screen shown here, that there is a 5th shortcut icon called PicoScope 6 automotive beta.
It is not necessary to have this software and this version may no longer be available. The reason why some peo-
ple still use it is so, they can run two or more Pico interface boxes at the same time on the same laptop screen.
This allows users to operate eight or more total channels while sharing a common sync input.

The software is constantly updating and improving functionality. It is your responsibility to decide if you want to
update your software or not. In PicoScope 7, there is a RED dot that appears in the upper right-hand corner
with a number inside of it indicating how many updates you are behind. Clicking on the RED dot links users to
the update page.
5
 PicoScope Advanced Features in PicoScope 6 & 7

Along with all the basic operations of lab scopes for everyday use, the PicoScope series offers some incredible
advanced features that we have addressed in our Advanced PicoScope operations class.

▪ Math channels – limitless possibilities

▪ Reference waveforms – including superimposing/overlays
▪ Triggers – 10 options depending on the scope/software
▪ Measurements – 19 built-in selections
▪ Serial decoding – several built-in protocols
▪ Masks and alarms – customizable messages
▪ Deep measurement – 12 searchable values
▪ Rulers/cursors – up to 12 partitions
▪ Low pass filters/resolution enhancement – capture them dirty
▪ Custom probes – limitless probe calibrations, units and values

All these advanced features require some practice to learn operation and their limitations. Proper use of these
advanced features will help us in developing new diagnostic routines.

PicoScope Advanced Mode: Viewing Options

▪ Spectrum analyzer: frequency base, instead of time domain

▪ FFT (Fast Fourier Transform) design
▪ Frequency (X - horizontal-axis), amplitude (Y - vertical-axis) measurements
▪ XY view
▪ Graphing to plot one channel against another
▪ Persistence mode
▪ Superimposing signals on the same screen live to help find intermittent glitches
▪ Multiple scope views
▪ The ability to open many extra views (scope, XY and spectrum) for individualized manipulations
▪ Channel zooming, masks, serial decoding, math, etc.

There are three advanced mode viewing options: spectrum analyzer, XY view and persistence mode. We
also have the choice of creating multiple scope views and within these multiple scope views, we can choose:
XY, scope or spectrum analyzer, even adding masks and alarms when necessary to any view. Persistence
mode cannot be viewed in any other view than itself. At the time of this writing, PicoScope 7 software only has
spectrum analyzer completed in both single and multiple scope views. Multiple scope views allows users almost
unlimited views, as we will see later. These may include: the scope, XY and spectrum views all on the same
screen. Keep in mind that masks and alarms can be generated in all views.

The Frequency Spectrum Analyzer: Unlike standard oscilloscope views which display voltage/amplitude over
time, spectrum view provides a different view by plotting the voltage/amplitude over the frequency. Spectrum
view can be used for finding the cause of noise/crosstalk in a signal which often looks abstract or random in the
standard oscilloscope view (time domain). It allows us to easily plot varying frequencies that could not be easily
recognized in the time domain view. While the frequency spectrum analyzer is not generally used in standard
automotive based diagnostics, it can be useful for testing distortion, frequency response and stability of
amplifiers, filters and oscillators. Collection features include: adjustable frequency range, bin width (line
spacing), logarithmic units and window displays. The spectrum analyzer in PicoScope is of the Fast Fourier
Transformer (FFT) types which can display the spectrum of a single, non-repeating waveform.

XY View: The PicoScope XY display mode plots one channel against another on the screen. This plot could be
the I–V (current-voltage characteristic) curve of a component such as a capacitor, inductor, diode or a digital
color: In this mode, all active channels employ the same color scheme. Areas of the waveform that have the

6
 Introduction to PicoScope 7

highest population density are displayed RED (hot), while the areas with lower population density vary through
YELLOW to BLUE (cold).

Analog intensity: Each channel is identified with its individual color (A = BLUE, B = RED, C = GREEN and
so on). Intensity grading is used to indicate the age or frequency of waveform data with the latest waveforms
drawn at full intensity and older data being represented by successively paler shades of the same color.

Fast mode: PicoScope uses the oscilloscope's rapid triggering hardware to capture waveforms at very high
repetition rates, over 100,000 waveforms per second on the faster scope devices.

The screen capture shown is an example of PicoScope 7 utilizing multiple scope views. We would agree that
this is a little crazy looking, but you will notice there up to 24 views in this software.

PicoScope 7 Example of Multiple Scope Views

This is just an example of utilizing PicoScope 7 software and multiple scope views. In this screen capture, you
can see that we're utilizing 24 different views of the same waveforms including math channels and differing
zoom and filter levels. In most cases, no technician is going to go to this level diagnosing a car. This example is
just to show how far your imagination can take you.

Most Common Pico Scope Unit Options

Pictured left to right: 3423, 4423 and 4823 with

release dates:

▪ Series-3423 – 2005 3423 4423 4823

▪ Series-4423 – 2009
▪ Series-4823 – 2019 (USB 3.0)

7
 The scope boxes are also found in two-channel versions: 3223 and 4223. Each
one of these scope boxes utilizes a common ground; therefore, each channel
is grounded to each other channel. The maximum incoming voltage to these
boxes ranges from 50 to 100 volts. It is important to note that if you expect an
incoming voltage to exceed the scope's maximum allowable value, attenuators
must be used.

The 4823-8 channel scope also incorporates a low voltage (±2 V) function/arbitrary waveform generator.
For most practical uses in our industry, this requires using an amplifier to produce useful signals. This scope
box is also one of the first to incorporate an internal ground accessible on the back of the unit (now available
on all). By grounding this terminal to the chassis ground of the vehicle, we can eliminate some of the noise
created by various computer chargers.

Latest Pico Auto Scope 4000 Series

▪ 4225 (2 channel), 4425 (4 channel)

▪ 200 volts maximum input
▪ Connect Detect
▪ Built in 20 kHz hardware filter (normal 20 MHz) 4225
▪ Must be turned on in analog options (Pico 6)
▪ Floating grounds up to 30 volts
▪ 4225A (2 channel), 4425A (4 channel)
▪ Powered probes (including resistance) , status lights
▪ Smart probe auto range detection
▪ Integration with Pico 7 guided tests (coming soon)

Release dates:

▪ Series 4425: – 2014 - Now discontinued

▪ Series 4425A: – 2020 4225A

It would be fair to note that as our technology progresses, we will also have differences in the USB versions.
These boxes all run on USB 3.0. It is also important to note that from a Pico standpoint, noise reduction is
of the utmost importance, and we should only be using the high-quality USB cables supplied by Pico that are
BLUE in color.

These scope boxes are also found in two channel versions: 4225, released in 2014 and 4225A released in 2020.
This series of PicoScope box has some significant advantages over the prior year's versions. In this series of
scope boxes, the channel grounds are floating to a level of approximately 30 volts. This can be advantageous
depending on the circuit being tested. These scope interfaces also have a maximum allowable input voltage of
200 volts.

One of the more obscure features of this series of scope boxes is a built-in hardware filter that allows low
pass filtering of the incoming signal from the standard 20 MHz down to 20 KHz. Low pass filtering basically
means that we are asking our scope to ignore (don’t draw) any signal that operates at a frequency faster than
our chosen filter value. The standard low-pass filter option that we have used for years in Pico has always
allowed us to filter our signal after the capture has been taken. This hardware filter, on the other hand, will
filter all signals before it is monitored by the scope box and therefore, should be selected carefully because it
cannot be removed after the capture has been obtained. In PicoScope 6, this feature must be turned on in the
analog options inside the preferences menu, before this option can be utilized. This feature is referred to as:
bandwidth limit in PicoScope 7 and does not require set up. The bandwidth limit can be found in the channel
options under vertical settings if the Pico interface is equipped with this option.

8
 Introduction to PicoScope 7

These scope boxes also include a feature called connect detect. This feature allows users to monitor the circuit/
probe connection integrity during test drives and can be extremely valuable when trying to determine if we lost
a signal or if our probe has become disconnected. We will explore these advanced features later in this class.

4225 (A), 4425 (A) & 4823 Differences

New Features – Not Found in Earlier PicoScope Platforms
The newest 4225, 4225A and 4425 and 4425A versions have some features not found in the earlier scopes. The
4823 has some unique features also of its own. We will cover these feature in this section of the class. These
scopes: (4225, 4425A, 4425 and 4425A) are now up to 400 MS/s, whereas the earlier 4000 series were only
80 MS/s. The 4823 is 80 MS/s with 1-4 channels and 40 MS/s with 5-8 channels. The even earlier 3000 series
was 20 MS/s. With the 4225 and 4425A, buffer memory is 250 million samples/number of channels used. The
4823 has buffer memory of 256 million samples/number of channels used and 10k waveforms.

The 3000 and 4000 series have 1 megohm impedance.

All three of this series of scope uses USB 3.0.

PicoScope 4823 Automotive Based 8-Channel Scope

We will start with the PicoScope 4823, 8 channel, automotive  8 - channels

scope platform. This scope has a maximum input voltage of  50 volts input maximum
50 volts per channel and utilizes common grounding between  Function/arbitrary signal
generator
the eight channels. Even though this scope box has the out-
– ± 2-volt amplitude limit
side appearance of the next generation 4225, 4425 series, it  Common channel grounds
does not share many of the newer features. Like, the built-in  Grounding set screw on the
hardware filter, floating channel grounds, auto probe de- rear
tect, connect detect, 200 volt maximum, 400 M/s sample
rate, etc. They truly are two different platforms with similar
appearance, but like all the automotive platforms, work on PicoScope 6, PicoScope 7 and Pico Diagnostics.

The Pico 4823-8 channel scope also incorporates a low voltage (± 2 volt) function/arbitrary waveform
generator. This type of signal generator also allows generating a user-defined waveform of any size, unlike a
standard function generator which can only generate a custom periodic waveform. For most practical uses in
our industry, this requires an amplifier to produce useful signal amplitudes. Function generators are something
we typically find in test and measurement scope boxes from Pico in the past. This was a nice addition to an
automotive based scope box. This is a feature not found in the 4225/4425 series.

This scope box was also one of the first to incorporate an internal ground accessible on the back (now available
on all). By grounding this terminal to the chassis ground of the vehicle, we can eliminate some of the noise created
by various computer chargers. This noise has been a bit of a challenge depending on the power supply being
used, some computers exhibited, some did not. In the past, when this noise was present, we just unplugged the
power supply to the computer, and it eliminated most of the issues.

4823 Grounding Screw & Signal Generator

Here is an example of the grounding stud (set screw) found on the

back of the 4823 and a photo of the arbitrary waveform generator output
and operation. When the 4823 is plugged in, the arbitrary waveform
generator icon populates in the upper right-hand side of the menu bar Grounding set screw

in PicoScope 6. In PicoScope 7, access to the generator is found on the

left-hand side under all the channel options.
9
 Arbitrary waveform generator

Arbitrary waveform generator

PicoScope 4225, 4425A, 4425 & 4425A

This series of boxes comes in two and four channel versions with a 200 volts maximum input. All the features
are the same, except for a difference in the number of available channels. In this series of scope boxes, the
channel grounds are floating to a maximum level of ±30 volts (must be grounded individually unlike the com-
mon ground designs). The ability to float a channel can be advantageous for some signal tests when we want to
utilize a ground different than the chassis ground. Examples: single channel voltage drop testing, VR/MR CKP/
CMP and other floating ground sensors, throttle bodies (with reversing polarity), etc. The caution here is that the

10
 Introduction to PicoScope 7

float must not exceed ±30 volts in potential difference. Care

must be taken when considering circuit operations such
as inductive kicks and VR style sensors that create higher
amplitudes with increased RPM. If exceeded, the scope will
protect itself, warn you with an LED on the front and produce
inaccurate results.

As we stated earlier, this series of scope boxes has a built-in

hardware filter that low-pass filters the incoming signal from
the standard 20 megahertz down to 20 kilohertz. Low pass
filtering basically means that we are asking our scope to
ignore (don’t draw) any signal that
operates at a frequency faster than
our chosen filter value. The standard
low-pass filter option that we have
used for years in Pico has always
allowed us to filter our signal after
the capture has been taken. This
hardware filter, on the other hand,
filters all signals before it is monitored by the scope box; and therefore, should be chosen carefully because it
cannot be removed after the capture has been taken.

In PicoScope 6, this feature must be turned on in the analog options inside the preferences menu, before this
option can be utilized. Yet this feature is referred to as bandwidth limit in PicoScope 7 and does not require
set up. It can be found In the channel options under vertical settings if the Pico interface is equipped with
this option.

These scope boxes and software also include a feature called connect detect. This feature allows users to
monitor the circuit/probe connection integrity during test drives and can be extremely valuable when trying to
determine if we lost a signal or if our probe has become disconnected.

There are some differences between the standard platform and the A versions. These differences in the A
models include:

▪ PicoBNC+: automatic probe recognition, push in connection, aids in set-up and reduces probe mis-match
in PicoScope 7
▪ PicoBNC+ powered probes: great for current probes because we no longer have batteries that die, and
we can run long term measurements and frustrating auto-offs
▪ PicoBNC+ Software Control: provides auto-zero on probes, current probe drift is now reduced also from
earlier battery powered probes
▪ Channel Status LEDs: helps with choosing the correct channels when using loaded waveforms
▪ These BNC+ connections are also 100% backwards compatible with all BNC accessories.
• These probes allow for some imagination for probes of the future. One example is the TA432 resistance
and diode test lead.

20 kHz Hardware Bandwidth Filter Locations

In PicoScope 6, the 20 kilohertz hardware bandwidth filter option must be turned on utilizing the show analog
options in the preferences, options menu. In PicoScope 7, it is much easier and will automatically populate
in each one of the channel options when a scope box with this capability is plugged in. Note: the hardware
bandwidth filter option will not populate unless a box with its capabilities is plugged in.

It is also important to understand that when using the Pico BNC+ current probes, they will automatically turn
on the bandwidth filter and it cannot be turned back off. There will be more on that later.
11
 Bandwidth limit

20 MHz Sample 20 kHz Hardware Filter Not Activated

We are demonstrating one of many uses where hardware filter selection can be advantageous. We are looking
at a high-speed frequency mass air flow sensor on a General Motors product. When choosing channel options
in PicoScope, we have the option of coupling DC, coupling AC or a measurement of frequency (counting).
Typically to count frequency, we would have to select a math channel and apply it. In some cases, this frequen-
cy counting option eliminates that one step. We are demonstrating the location of the frequency measurement
option in both PicoScope 6 and 7. We can see that the frequency varies wildly from about 2,000 Hertz to well
over 20,000 Hertz. When zoomed in, we can see that this is not a usable waveform due to the large frequency

12
 Appendix
Introduction to PicoScope 7

spikes. This capture was obtained using the 20-megahertz bandwidth setting. This is the standard bandwidth
utilized in this series of scopes.

The channel frequency counter is adjustable in coupling AC/DC, device voltage, and upper and lower thresholds.

Coupling mode
Bandwidth limit

Frequency

13
 20 MHz Bandwidth Sample on GM MAF Frequency

We are now going to look at the 20-kilohertz hardware filter option available in this scope (4225, 4425 and
A) series. Both waveforms are the result of the 20-megahertz bandwidth standard setting. The option of turning
on the 20-kilohertz bandwidth limit is found in each one of the individual channel selection options (A, B, C
and D) in PicoScope 6.

Keep in mind that this option is a true hardware filter; and therefore, filters the signal before any software ad-
justments are performed. This means that if selected, it cannot be reversed once the waveform is captured and
stored. When choosing this option and reducing the bandwidth, we still will have the option of applying all the
standard filtering/resolution enhancement techniques that we have used in the past.
14
 Introduction to PicoScope 7

None

20 kHz

20 kHz Hardware Filter Activated

This is the result after applying the 20 kilohertz hardware filter. By reducing the bandwidth to 20,000 cycles per
second, we have eliminated the noise that was originally in our waveform. This signal now truly represents the
actual cycling frequency of our mass air flow sensor. The frequency changes from approximately 2,000 Hertz to
approximately 7,000 Hertz due to us increasing and decreasing the vehicle’s RPM. When we compare this signal
to the true signal value of this mass air flow sensor, we will be able to get the whole picture on waveform quality.

15
 Hardware Filter Activated on A, Signal Voltage on B

We are now looking at two channels: channel A pictured on the bottom in BLUE is our chosen frequency
channel. Channel B pictured on the in top in RED, is the true signal value. Our true signal value looks like
a big RED brick due to the timebase that we have chosen of five seconds. We really do need to analyze the
changes in frequency during this period without spending the time-consuming process of monitoring screen
after screen after screen. In this case, we can see the frequency changes based off the channel A results. It is
true that in order to look at waveform quality, the true cycling of the waveform, we need to zoom in and obtain a
magnified image. At least in this case, the frequency changes of the signal truly represent the RPM/air volume
changes of the engine.

Channel B: true signal

Channel A: frequency

16
 Introduction to PicoScope 7

Adding Two Math Channels to Channel B

Channel B: true signal

Channel A: frequency

Duty cycle

Calculated frequency

Now we are making a comparison of:

▪ RED: channel B on top – the true signal value

▪ BLUE: channel A second from the top – true frequency measurement/counter from the channel menu
on channel A
▪ BLACK: channel 3rd from the top – math channel duty cycle percentage of true channel B data
▪ PINK: channel on bottom – math channel frequency calculation of true channel B data

Using this view, we can now see that the 20 kilohertz bandwidth hardware filter produced a perfect frequency
reading/calculation of our mass air flow sensor. This is now verified by our other math channel selections. Not
only do we have perfect frequency variances, but a relatively stable duty cycle also. This once again is a known
good example.

4225, 4225A, 4425 & 4425A: Connect Detect Option

These versions of scope box (4225, 4425A, 4425, and 4425A) provide users with the option of connect detect.
This feature only works on the x1 probes (standard voltage) which means none of the non-attenuated probes
will work with this feature. The idea here is to create a warning system to let us know if we have a signal that
dropped to zero/went open, or if we develop a connection issue with our scope hookups. All of us that have uti-
lized test equipment have run into situations where we get results that weren't true results. Results were faulty
because our connection was not complete, or basically our probe fell out.

This feature monitors the circuit. Anytime the resistance/impedance gets higher than 100,000 ohms, it is
considered a disconnected/open circuit. This feature is updated at the end of each buffer; so, the faster the
time base, the quicker the update (at least in PicoScope 7). PicoScope 6 is slower and will not respond as
accurately unless you are running a time base in the slow sample mode, typically 200 ms (default) or slower
(that setting is adjustable in the preferences menu). One more note
about PicoScope 6, if you select a channel with frequency coupling,
none of the other channels’ connect detect will work. This is not true
in PicoScope 7. In PicoScope 7, it will automatically just shut off the Connect Detect
frequency channel. The others will still work.
17
 If no connection issues are noticed at the buffer update, then the connect detect warnings will go from GRAY
to GREEN for up to few seconds between buffers. In the event of a connection issue or an impedance higher
than 100,000 ohms, we will have a RED warning. We need to be careful when trying to use this feature for
true circuit diagnostics when looking for intermittent opens because it can be deceiving in that it requires a lot of
resistance before it triggers the RED warning. Where it seems to have the best usage is when we are making
sure that our connections have stayed stable during our test drive.

Connect Detect Menu Locations

The menu locations

for connect detect
auto populate if a Pico
box that utilizes the
function is plugged
in. In PicoScope 6,
the menu appears
as GREEN and RED
icons at the end of
the channel selection
screen. Utilizing the
drop-down menu from
there, you can select
how many channels to
apply connect detect
to. In PicoScope 7,
the connect detect
function will populate
in the more section
and then like any other icon, you can star it to be a standard menu on the left, below your channel options. In
PicoScope 7, it will automatically turn on connect detect for any channels that are functional.

18
 Introduction to PicoScope 7

PicoScope 7, Connect Detect On During Signal Capture

The first screen capture is what the connect detect system looks like during a standard screen capture with the
channel selections GREY. Once we get to the end of the buffer and begin our next filling, we get the results of
our connected ticked like screen as seen in the top capture. In this top screen capture, we can see that all four
channels are considered to be in good circuit connection, or to say that those circuits had less than 100,000
ohms of impedance. PicoScope 6 is very similar in operation.

19
 PicoScope 6 Connect Detect Example on 4 Channels

Here is an example of connect detect in the PicoScope 6 software showing normal and then a failure of channel D.

We Have Lost Channel D for a Few Seconds

In this capture, we have lost our connection at channel D for a few seconds and as the buffer update shows,
channel D has turned RED representing a high level of impedance in that circuit. When and if channel D comes
back to life, it will then again cycle back to GREEN. When using connect detect, it is a little bit slow to update, so
a rapid intermittent open connection most likely will not be recognized as a circuit failure unless you choose the
proper (faster) time base. You will want to practice with this feature before relying on it for test drive diagnostics.
20
 Introduction to PicoScope 7

Understanding the Detect Failure

One of the reasons we need to practice with this feature is demonstrated in this screen capture. Notice that we
have lost full connection to channel D twice in this buffer within the five seconds. Because the connection was
repaired again by the end of the buffer, it was not counted as a connect detect failure. So, the results of this
were GREEN across all four channels when progressing into buffer 6.

In a situation like this, it would have been smarter to make the time base faster, so we would receive more up-
dates over a shorter period of time. This would have allowed us to see that we had a probe connection issue.
that was intermittent.

Example of Connect Detect Auto Setting for Channel - C

Pictured at the top of the following page is an example in PicoScope 7 where connect detect has eliminated the
option for channel C. Looking closer at channel C, you will notice that it is a frequency counter channel; and
therefore, is not eligible for connect detect. The same thing happens when using attenuated probes like pressure
transducers, current probes and capacitive ignition probes, etc. In our opinion, Pico 7's version of connect detect
is a more user friendly and accurate option.
21
 Pico Operation & Set-up

In this section of the class, we will explore basic PicoScope software setup and operation. We will be utilizing
case studies to show these operations and more in action, further in the course.

Start-Up Screen Without a Pico Scope Box Attached

One of the nice things about the Pico software is that it can be downloaded and operated in demo mode for free
without connecting a PicoScope interface. This is something that should be considered by every lab scope user
whether utilizing the true PicoScope interface or not. There is a lot of information available in this scope software
that can be used for setting up other scope interfaces. This also provides great practice for all technicians when
they're not at the shop, they can do this at home in practice.

Demo mode

22
 Introduction to PicoScope 7

Scope Detected Screen

This is the more common screen

that shows that there is demo
mode and a Pico box available.
If you have more than one box,
they will both show up at this
time. Also, you'll need to choose
which box you want to use on
this software. This is also the
screen that pops up when you
press the connect button in
the options menus. This is
sometimes necessary when the
box loses communication with
the computer.

Common Issue With Some USB Cables & Ports

This is a situation that we are hearing quite frequently these days. In every case that we've run into, this does
wind up being a problem with the quality or the length of the USB cable and/or the port on the computer. Pico
is very strict about the quality of their USB cables, and they recommend that you only use their supplied cables
with their Pico interfaces.

First View After Choosing Demo or Box Selection

Whether you choose demo or a particular Pico interface, this will be the next view that you see on the screen
and unless deleted (don’t show again selection), the automotive testing guided tests box will pop up. Even if

23
 you don't see this box, you can always pull this option box up by clicking on the car icon called guided tests
located at the center top of the screen.

Another note to make on this screen is the small RED circle with the number one in the middle in the upper
right-hand side of the software. This number represents how many software updates that you are behind. The
Pico scope 7 software is updating at a tremendous rate right now and it's very common to see several numbers
inside this RED dot. It is our advice, when you see this, to update your software at your earliest convenience
because most of these updates provide extra operations and bug fixes.

Guided tests Red circle

Red Dot: Update Reminder Example

Here is an example of pressing the RED dot from the upper right-hand corner and getting a list of what these
updates are going to install.

24
 Introduction to PicoScope 7

PicoScope 7: Information Example

Now let's break down some of the incredible features found in the guided tests section in PicoScope 7.

When opening the software, this guided test box opens automatically. It is also accessible under the guided
test button located on the top of the screen. There is an incredible amount of information here including guided
tests and setups for many automotive diagnostic procedures. There is also that don't panic button. It is our
recommendation that everyone of you spend some time in the don't panic section of this information menu
due to the incredible amount of help provided here.

Guided tests Auto setup

Don’t panic

PicoScope Guided Tests, Sensors Example

After pushing just one of the buttons called sensors from the previous page, we get a drop-down menu of
many of the more common sensors that most of you will recognize in the automotive industry.

25
 Crankshaft Position Sensor (CKP) Options

Once you select the sensor/circuit, you receive a pretty good description of how the circuit works, some tips
and tricks for diagnostics, and hook up instructions for your scope leads. After exiting all this cool information,
your scopes x axis and y axis will be set up. In our opinion, it is not always the best time and voltage levels,
but it does get you started. Your channels will be designed with the auto setup for the correct probes and you're
off and running.

PicoScope 7: Guided Tests

The options in guided tests are pretty cool. In this example shown at the top of the followiing page, we are
showing you just one of several EV/hybrid test methods on a resolver sensor. As you can see on the right-
hand side, based off the scroll bar, there is a lot more information that can be obtained here. It’s our advice, as
stated earlier, that you really spend some time in guided tests looking at all the features that Pico software has
at your fingertips.

26
 Introduction to PicoScope 7

DPF Testing Guided Test With Auto Probe Set-Up

In this next example, we are showing you another one of the guided tests that's utilizing a completely different
probe set up: the WPS500x. Notice that even in the probe selection options, that it has automatically set up
for this probe.

27
 No/Wrong Probe Selection Upon Running the Waveform

If you do not plug in the proper probe or no probe at all, when you start running the waveform, the scope will
automatically pick this up and warn you with your mistake. These are features that are added to PicoScope
7 that were not available in PicoScope 6. It is just another reason why, that in our opinion, the PicoScope 7
software is better than PicoScope 6.

28
 Introduction to PicoScope 7

Timebase Selection

As we can see in this screen capture, at the upper left corner of our software, is the start, run and stop button.
To the right of that is our timebase and sample rate selection button. In PicoScope 7, it is nice that they've
added more to this box than just the timebase. You can also see in smaller writing, the number of samples
and sample rate per second. In PicoScope 6, we would have had to look in properties to find this information.

This box can be used in two different ways: you can either use the positive and negative selections to in-
crease or decrease the time base, or you can simply click on the entire box which opens the menu as seen
on the screen here.

Start, run or stop

Timebase

Sample rate per second

Sample Rate Selection

There are some basic settings in the sample rate selection that makes sample rate adjustments easier. This
also gives us the ability to manually adjust our sample rate to whatever we are trying to achieve. It's going to take
a little bit of practice for most technicians to get a handle on true sample rate per second and total number
of samples. These numbers both change as we add or subtract time base and add or subtract channel num-
bers. You will also notice the scope provides us with the automated setting on whether we are paying attention
to buffer capabilities or true sample rate. We typically pay more attention to sample rate than buffer quantity.

We always recommend that we achieve a sample rate that is 10 times faster than the circuit being tested. It is
nice that Pico set the default to 2,000,000 samples per second, which in most cases, is more than adequate
for our testing. We will need to adjust the sample rates when we get into faster circuits like high-speed commu-
nications. For example, when looking at high speed CN-C at 500,000 bits per second, we typically recommend
a sample rate of at least 5 million samples per second.

29
 We also see the option to adjust the progressive mode timebase. This number has an impact on the way the
waveform is displayed on the screen, whether it is a free run or a wait until all samples are collected to display.
We also notice that Pico has put a little information icon (lowercase i) near some of the more confusing settings
to help users simply just click on that for information.

Sampling

Sample rate

Target sample rate

Information
Progressive mode

No Trigger Selection

Trigger

30
 Introduction to PicoScope 7

Triggers are used for viewing options only. The trigger has no effect on how the scope samples from the circuit
being tested. Yet triggers can be very useful in locking in a particular waveform (or part of the waveform) on the
screen, or only drawing a picture when it meets our criteria, typically voltage level/slope. In this view, the scope
is set up for no trigger selection which means it will just free run the waveform as it samples it from the vehicle.
There are several reasons for utilizing triggers. In some cases, triggers can help us diagnostically to capture
intermittent issues like powers or grounds. Or maybe we just want to use the trigger to lock a cranking relative
compression waveform on the screen because we can't stop the scope in time personally. Triggers can also be
useful for extended time parasitic draw testing to lock on when something happens.

We take a lot of waveforms with our Pico software and find that in many cases, we don’t even set up a trigger
because the free run option and the massive storage capabilities of the scope don't require it. Although masks
are not yet available in Pico scope 7, triggers are imperative when utilizing this advanced Pico option. Masks
and alarms are covered in our advanced Pico scope class.

Trigger Selection Options

Trigger selection options come in many flavors in Pico. Basic trigger options contain auto, repeat, and sin-
gle. Typical adjustments are for slope and position on the screen (voltage and time position). PicoScope also
allows us to choose which channel that we want to use for the trigger. Pico utilizes a YELLOW square on the
screen to indicate trigger position. It can simply be grabbed and moved to any position you desire.

Keep in mind that setting a trigger tells the scope not to draw the waveform until the trigger values have been
met. The PicoScope does a great job of still showing you some information in case you get the trigger setting
correctly. That is not what we see in most scopes.

For those of you who have heard of the Pico gap, setting a trigger out of reach can help you from getting into
that situation. There is more on that topic in our advanced Pico user's class.

Auto Repeat

Channel

Trigger position

31
 Example of Auto Trigger in Demo Mode

All the trigger functions will work great in demo mode, and we suggest practicing with all the trigger options
while in demo mode to get a feel for how the slope changes and what each trigger does. As you can see in this
screen capture, this trigger is in auto setting on channel A with a positive slope with the positions indicated
in the menu.

Auto mode
Channels

Channel A

Rising Channel B

Utilizing Trigger to Lock an Injector Signal on the Screen

We are still in demo mode, and we have adjusted the timebase and adjusted the trigger to lock the event in
the middle of the screen. The trigger settings can be read in the trigger box located on the top of the screen.

Stopped Trigger settings

Auto mode

32
 Introduction to PicoScope 7

Advanced Trigger Selection Options

Advanced trigger selection options have many different capabilities. These different options can be very useful
for different types of waveforms and require some practice to play with. We have included quite a bit more on
this topic in our advanced PicoScope operations class; however, the pictures and descriptions in the software
do a pretty good job of giving you an idea of what it's going to lock on. One of the many uses where we use
advanced trigger selection is for locking on a waveform that has a sync pulse like we see in this crankshaft
waveform in BLUE channel A below.

Buffer Library & Capture Time

Waveform buffer library

Capture time

Buffers

33
 Pico has done a great job with the way they display the buffer library. By clicking on the waveform box located
at the top of the screen, the buffer library will open, and we can see all our captured screens. If you click on
the waveform box, it will open the waveform navigator which will now provide us options to adjust the size of
the display of our captured buffer screens. You will also notice underneath that, we can add the capture time
and date to our waveform. We think it's important to realize now that all these functions can be performed after
the waveform has been captured and saved, so we can't make any mistakes.

Keep in mind the number of total buffers that can be captured are based off the storage capacity of the scope
box itself, and will vary based off channels used, timebase, and sample rate. For example, if we use a lot of
resources on one screen, we will not get many buffers, but if we have fast time basis, we will get more buffers.
This too is a topic that must be practiced in the shop, so you get an idea of what your option selections produce.

Buffer Library on XL Setting

This is an example of changing the view selection in the waveform navigator to extra large.

XL

All 64 Buffers Shown on the Screen

64 buffers is the default number for PicoScope 7, although it is a truly adjustable number, as we will see in the
next screen capture. One of features of PicoScope 7 software is the ability to click and drag on lots of different
options; therefore, we are able to display all 64 buffers on one screen by simply grabbing the bar and pulling it
down.

34
 Introduction to PicoScope 7

100 Buffers Collected

Here we can see 100 buffers pictured all on the same screen. This was achieved by adjusting the Max buffers
option as seen above.

Max buffers

35
 Save File Selection

The save file selection which is located on the top of the screen is an incredible feature and should be utilized
anytime a waveform is captured. We don't necessarily fill out all the available information slots, but we do put
as much information as possible in here so it can be easily searched and re-opened for future reference. This
also gives us the ability to choose where the waveform is saved. There is a notes box where we can add an
incredible amount of notes about the vehicle we are working on and once again, we suggest we do our best at
that as you can see on the screen below.

It would also be good to note that when properly saved, a waveform can be opened and utilized with all the same
presets on other vehicles. For example, when you take a relative cranking compression test, and you love the
settings on one vehicle, save that as a generic relative compression waveform setting to be utilized later.
You will need to practice with that, but it will improve your efficiencies with the scope.

Save file

Notes

Vehicle Details

This screen capture pictured at the top of the opposite page is an example of the vehicle detail screen where
we can easily enter details of the vehicle. This will transfer into the save file when saving.

36
 Introduction to PicoScope 7

More Button
On the left-hand side of the screen, underneath the channel selection boxes, are several buttons, one of which is
the more button. When clicking the more button, the software opens all the options that the scope has available
for us, as you can see most of them on the screen. By clicking the star next to each option, the software will
put it in a quick select menu underneath the channel options where in this picture you see things like rulers,
measurements, math channels, etc. You may notice in this more menu, that some of the items are GREYED
out. These functions are not yet completed for PicoScope 7, but are on their way.

We will be covering all these options by the end of this class and many of which we will also include in our small
case studies.

More

Quick select

37
 Great Waveform Library

Under the more tab, is a button called waveform library. PicoScope seven has moved to a 64-bit program to
ensure the safety of their waveform library. The waveform library in PicoScope 6 is being removed; therefore,
this will be the only Pico waveform library available. The waveform library will not be accessible without a Pico-
Scope interface plugged into the software. This is one of the few features that truly requires a scope box to be
attached to the computer to access. Once the Pico box is plugged in, you will need to set up a username and
password for this amazing free resource.

Waveform library

Waveform Library Tesla Example

38
 Introduction to PicoScope 7

At the time of writing this class, there were well over 7,000 stored waveforms in this library. The search engine
is incredible and can be very broad or very exact depending on your needs. Once you find the waveform you're
looking for, it can be downloaded into your computer in a raw file so you can manipulate it any way you see fit.
This is accomplished using the little box with the arrow in it in the right-hand upper corner of each waveform.

Settings Button

Another button accessible in the more column is for settings. This is self-explanatory. One of the options avail-
able here is dark mode.

Settings

Light or dark mode

Dark Mode

In this screen capture, we have an example of dark mode. You will notice in this class that most of the waveforms
are captured in dark mode because they seem to work better for us. It should also be noted here that when
any channel is selected, the color/line thickness can be changed to anything you want.

Trace line thickness

39
 Filters & Resolution Enhancement

Although there are differences between filters and resolution enhancement, filters provide users with more
adjustability. Software filters have no impact on the signals that are coming from the vehicle. They just change
the way that we display the signal for our viewing pleasure.

Keep in mind that the low-pass software filter is not the same as the hardware filter discussed previously
that was available for the 4225, the 4425 and A version of scopes.

It is also important to note that not all noise is bad. In many cases having noise in the waveform can help us to
diagnose issues that may not have been seen with other test methods like ignition issues and such. Noise can
also be used for synchronizations.

Our philosophy is to capture them dirty because in the Pico software, we are allowed to add filters at anytime
after the capture has been taken and saved, or if we want to apply them during the capture. Another great feature
of Pico filters is that with the massive amount of adjustment, we can filter just about any waveform at almost any
capture rate that we take. There is a downside to this, however, as you will see that you can get too aggressive
with the filter and destroy your waveform.

There are other filter options inside the math channel capabilities of this scope. These are discussed in our
advanced Pico class.

No Filter, 2 ms Sample Rate

Here is a standard screen capture of three waveforms: both camshafts and crankshafts collected without soft-
ware or hardware filters installed.

40
 Introduction to PicoScope 7

Low Pass Filter Example on Channel C @ 1 kHz

Here is an example of adding a filter to the channel C camshaft sensor shown in GREEN. We originally had
the view of the camshaft sensor in channel B RED. You should be able to see that our choice in filter was 1,000
Hertz. What this means is that we are asking the scope to ignore all signals happening faster than 1,000 cycles
per second. So, in this case, it took some of the fur or noise out of that camshaft sensor signal without destroying
the base signal. Once again, keeping in mind, that it only changed our view, not anything on the vehicle.

Low Pass Filter Example on Channel C @ 32 Hz

41
 In the example pictured at the bottom of the previous page, we have taken the filtering to much more of an ex-
treme and asked the scope to not display any signal faster than 32 cycles per second. It should be very easy
for you to see that our filter selection has destroyed the waveform to the point that it is not usable. Care should
be taken when applying filters to make sure that we do not affect the amplitude nor switching rate of any signal.

Resolution Enhancement Locations

The menu location for vertical resolution enhancement is found in the channel selection menus in both
PicoScope 6 and 7. As the menu shows in PicoScope 6, we can adjust 4 total bits (in .5 increments). That is
the same value in PicoScope 7. When resolution enhancement is utilized, the value will show up in properties
in Pico 6 and in the channel box in Pico 7. Resolution enhancement like filters can be adjusted (higher or lower)
even after the waveform is captured and not live.

Channel box

Resolution enhancement

3- Channels:- Same Signal Raw, Enhanced & Low-Pass Filter

Low pass filter

16 bit resolution

Raw waveform

42
 Introduction to PicoScope 7

This is a demonstration comparing resolution enhancement, low pass filtering and raw signal data. Although
there are some minor differences in the display between resolution enhancement and filtering, they are really
similar to each other, and with practice, you can make your decisions on which you would like to use. We find
that low pass filtering is typically a better option due to the massive amount of live adjustability. When using
resolution enhancement, the steps can be more aggressive. Whichever way you decide, they can be adjusted
once the waveform has been captured and saved, so your decisions are not final. Neither of these methods
affect the way the sample is captured, just the way it is displayed. Keep in mind while we are on this topic, that if
you do utilize the 20 kHz hardware bandwidth filter previously discussed in this class, those choices are final
once the waveform has been saved.

Measurements

We do not want to confuse measurements with the option of deep measurement that is listed under More
options. They are truly two different functions.

Deep measurement is an incredible feature that we have outlined in detail in our advanced Pico user's class.
At the time of writing this class, deep measurement was not available in PicoScope 7 only PicoScope 6.

Measurements are going to allow us to ask the scope software to perform some very basic measurements.
These are going to be measurements found in most scope platforms We must calculate ourselves based off
cursor measurements.

Measurements PicoScope 7

Measurements in PicoScope 7 can be found by clicking on the More menu. A word of note, any items that are
found in the more menu can be starred and put to the quick menu underneath your channel selection area.
Once they are selected, the star will turn from hollow fill to solid fill. The add measurement selection in Pi-
coScope 7 has all the same features as PicoScope 6, but is laid out in a more user-friendly fashion with pictures
to indicate the measurement concept. This makes it easier to understand for new users.

More menu

Measurements

43
 Add measurement

PicoScope 7: Measurements Example

We are now looking at a lot of measurements taken off this waveform including from different channels. We know
this appears to be overkill, but we're just trying to demonstrate how many options are available.

44
 Introduction to PicoScope 7

Channel Coupling Options

Channel coupling options come in three varieties in PicoScope 7: direct current (DC), alternating current
(AC), and frequency. As with filters, channel coupling options do not affect the true signal on the vehicle, but
they do change the way that we view signals on the scope.

AC vs. DC Coupling Example

Here is a simple example of AC coupling versus DC coupling. In DC coupling, in the first screen capture,
we can see all the voltage that the circuit has available. When we switch to AC coupling, we have asked our
scope to display only the alternating current or alternating voltage that is on the circuit. We are looking at a good
charging system from an overall DC standpoint of total voltage and the AC coupled view of the diode pattern.

45
 Frequency Counter Option Locations

Here are the locations for the frequency counter options in PicoScope 6 and PicoScope 7. They are found
within the channel options. There are a few adjustable options for this frequency counter: upper threshold,
lower threshold coupling of AC, DC and device input range. When you enter this mode, it typically chooses
AC coupling as the default and picks its own upper and lower thresholds. These readings are almost always
perfect for what you are trying to do, but if necessary, can be adjusted.

There are lots of different applications where having a live frequency counter can be advantageous. This may
help to eliminate the step of building a math channel to provide that information. The frequency counter can
only be used on one channel at a time, so if more frequency measurements are required, math channels will
have to be added.

Frequency counting

Varying Frequency Example

Frequency

46
 Introduction to PicoScope 7

Pictured at the bottom of the opposite page is an example of a digital signal with a varying frequency. As you
watch the frequency graph (GREEN on the bottom channel C), we vary from approximately 6 hertz to almost
2,000 hertz. This is very useful because during the faster frequencies in this sweep, it just looks like a big block
of color. This is an advantageous way to sample when looking for drops up or dropouts in high-speed frequency
signals. There are many uses for this feature. One of the more common uses is when looking for frequency
variations in high-speed mass air flow sensors like found in many General Motors products.

Introduction to Math Channels

Math channels are going to allow us to ask our scope software to perform equations to our waveform to aid
us in diagnostics. The capability of math channels in Pico is incredible and your imagination is the only thing
holding you back. We are only going to discuss a few basic options here, but we have an incredible amount of
math channel operation in our advanced Pico user's class.

PicoScope 7: Math Channel Location

PicoScope 7 math channel location and operation is quite a bit easier than in PicoScope 6. When utilizing math
channels in PicoScope 7, the mathematical equations are more automated and require less equation skills.
We can also see that there are more standard built-in math channels including RPM for two of the most common
crankshaft signal counts.

47
 PicoScope 7: Math Channel Wizard Example for RPM

This is a demonstration of the accuracy of math channels and ruler guided RPM measurement in PicoScope
7. Note that a custom math channel for channel C of the crankshaft sensor was built. This was easy because
the equation was already provided and all we had to do was fill in the channel and the number of teeth.

48
 Introduction to PicoScope 7

Frequency Math Channel Example

One of the most common uses for math channels is to automatically measure the frequency of a signal. This
allows us to graph the frequency over a period of time like a crankshaft sensor or mass air flow sensor or the
like. There are many different things we may wish to measure from a frequency standpoint. In the graph shown
here, we can see a crankshaft position sensor on BLUE channel A and then the frequency of that crankshaft

49
 position sensor in RED. We can see the expected dropouts in the signal where the sync pulse goes by and what
appears to be a very even crankshaft position sensor acceleration. Yet in this picture, we have not adjusted the
range of the frequency and therefore, the smaller details are left out in the capture.

Frequency

Crankshaft position sensor

Frequency Math Channel: Edit Range

Edit math channel

Range

50
 Introduction to PicoScope 7

We are now using the edit button to edit the variables we want to use on this frequency math channel; but in
this case, all we are going to adjust is the range of the frequency from minimum to maximum. This allows
us to obtain greater graphing detail of the acceleration and deceleration of this crankshaft. This setting would
commonly be used to look at crankshaft acceleration to determine if misfires are present in a particular location.

Frequency Math Channel: Edited Minimum/Maximum

Now, after adjusting the range, we see the results in the acceleration and deceleration of the crankshaft with
far more detail. It appears to be very even representing no obvious misfires. This is a very complicated and
time-consuming concept to learn and it is going to require some practice. We have had situations where a mis-
fire was difficult to see using this type of testing technique. In the same respect, we have used this technique to
locate misfires successfully. This technique is not absolute, yet in our opinion, is still useful.

Frequency

Crankshaft position sensor

Horizontal Magnification Displays Detail

Now that we’ve applied some horizontal magnification and zoomed in for some detail, we can see the nice
rhythmic speeding and slowing of the crankshaft, indicating no lack of cylinder contribution.

51
 Misfire Example 4.7L V-8 Engine: CKP Frequency Graph

Cylinders

7 8 7 8
1 4 5 6 1 4 5 6
2 3 2 3

Frequency

In-cylinder compression

Here is an example of a misfiring cylinder on a typical V8 engine. If you notice, we can see channel A in RED,
displayed at the bottom of the screen, is an in-cylinder compression waveform. The engine is definitely mis-
firing on that cylinder. We recommend using this procedure when practicing to learn this technique because
if we look at the frequency graph shown in BLACK in the middle of the screen, we can truly see all 8 engine
cylinders and the overall slowdown when our in-cylinder compression waveform should have been speeding
the crankshaft up. You can definitely see the slowdown. This technique helps us better understand crankshaft
acceleration and frequency.
52
 Introduction to PicoScope 7

Math Channels in Use for Data Communications Analysis

Math channels are extremely useful to technicians when performing diagnostics. We are asking our scope to
perform the math for us by programming a math channel with a mathematical equation. Then the lab scope
software performs the calculation for us using the data in our waveform. Here is an example of using a math
channel for data communication with a signal on the high speed (HS) controller area network (CAN) 500 Kb/s.

In this screen capture, we see an extremely noisy, but normal high-speed signal over the GM local area network
(LAN). The noise in the signal is due to the electronic throttle-by-wire motor.

The capabilities of math channels using Pico software is incredible and the possibilities are endless. We are
only going to discuss a few basic options here in this class, but we explore the advantages of math channel
operation in much greater detail in our advanced Pico user's class.

Horizontal (Time) Magnification For Detail

In the next screen capture, we magnify the same signal using a noisy high speed controller area network
(CAN) waveform.

53
 Math Channel Location for A-B

In this screen capture, we can see the location of math channels as seen in the menu in PicoScope 7. We have
selected the equation: Channel A – Channel B.

Math Channels

A-B
A-B

Magnification: Zoom-in Detail

At this level of magnification, it is very easy to see that the math channel of A - B has made this a very usable
and normal communication waveform.

A-B

A-B

A-B

54
 Introduction to PicoScope 7

Using Two Math Channels Example: A-B & A+B

We obviously have some communication issues going on here, but surprisingly enough during some of it, the
math channel operation looks OK. We should be able to see that towards the right-hand side of the screen, it is
quite corrupt and repetitive. Notice that we are using two math channels in this instance. This also demonstrates
that we can add more than one math channel depending on what we're looking for.

High speed CAN-C network

High speed CAN-C network

High speed CAN-C network

High speed CAN-C network

Math channel

Math channel

Reference Waveforms
Reference waveforms allow us to save known good or known bad waveforms and transfer them into the
viewing screen of another scope view. In our opinion, reference waveforms are a little difficult to use. Like
anything else, using reference waveforms effectively requires some practice. We find that using an overlay
program available from the Windows App Store is often easier. We will discuss a windows overlay program a
little bit later in class.
55
 PicoScope 7: Reference Waveform Locations

This screen capture displays the location of reference waveforms using PicoScope 7. Reference waveforms
are found under the more button options.

More

Reference waveforms

Saving Reference Waveforms in PicoScope 7

Save

56
 Introduction to PicoScope 7

Once you have established a reference waveform, utilize the save button to move it to a folder on your com-
puter. At that point, the waveform can be named appropriately.

The Save Button Opens the References Folder

The save button opens the references folder automatically and here we can properly name and store our
reference waveform.

References folder

Name and store

Utilize the Open Button > Files to Access Stored References

Open

Files

57
 The Reference Waveform is Now Visible in All Buffers

We can now see that the reference waveform has appeared on our screen, but better yet, has appeared in all
of our buffers. It is at this point that we can make any of our standard reference waveform adjustments, as
necessary. Keeping in mind with all of the options available to us, we still cannot change the timebase of a
reference waveform. As mentioned earlier, using other available software programs can help with this situation.
The other choice we have here is to open up another scope view and adjust the timebase in a second scope
view for our necessary comparisons.

Time Delay Box Adjustments

Time base

Type in the offset

37.99 ms

Vertical rulers

58
 Introduction to PicoScope 7

Here is an example of the time box delay adjustment capabilities in PicoScope 7. Pico has made it easy to
simply type in the amount of offset that you are looking for. In this example, we have used vertical rulers to
determine the amount of advance and or delay that we want in our waveform. In this case, we selected 37.99
milliseconds. We will share an example of the time delay box in a few slides.

Not a Perfect Overlay?

Here is a very common example of what happens when your reference waveform and your true waveform
are captured using a different timebase. In the next two captures, we will see that the engine RPM is different
between the captures of these two pictures. This is an important concept to realize when trying to do use overlays
with the Pico reference waveform software.

RPM of Reference Waveform 486.3 x 2 = 973.6 RPM

In the next example, we can see that the RPM of the engine when the reference waveform was captured equals
973 RPM. As seen in the next picture our true waveform shown in BLUE was taken at 1,009 RPM. Although
30 RPM or so doesn't seem like much of a difference, we can see that it makes a substantial difference when
trying to compare one cylinder to another cylinder utilizing this style of overlay.

59
 Reference
Actual

RPM of Known Good: 504.5 x 2 = 1,009 RPM

This poses a problem when trying to properly match one reference waveform against another. There are a
couple of solutions to this problem.

We can use an aftermarket third party software to allow us to stretch the waveforms, as seen later in this class.
We can utilize a second scope viewing screen as seen in the next picture.

504.5 RPM

60
 Introduction to PicoScope 7

Example: Second Scope View With Reference Waveforms

Here is an example of using a second scope view to be able to utilize the horizontal zoom for comparison of
a camshaft and crankshaft position waveform. In the first screen capture, we can see that the lower waveform,
scope view 2 (known good reference) has a time base that does not match our live scope 1 capture. This
is one example of how we can adjust the horizontal magnification to achieve our goal.

In the second screen capture, we can see that we have adjusted the scope view shown on the bottom, which is
our known good reference, so we can more easily see the difference in camshaft/crankshaft synchronization.
This is also a good time to point out that we have renamed our scope channels. The channel pictured on the
top is our camshaft and crankshaft from our vehicle and the channel pictured on the bottom is are known good
reference. The ability to rename your scope views can be found in channel management within the views menu.

Although we have used PicoScope 7 to demonstrate this feature, it is a feature that can also be utilized in Pico-
Scope 6 in nearly the same fashion.

Live

Reference

Live

Reference

61
 2007 Chevrolet 5.3L: P0303 Reference Waveform Example

Here is a great example of utilizing reference waveforms to build a waveform overlay for the in-cylinder pressure
signatures comparison of two cylinders. In this case, we have two WPS500X pressure transducers installed in
two cylinders simultaneously. This assures that the RPM is exactly the same during this test and will allow us to
use our software to overlay the results.

2007 Chevrolet 5.3L P0303: Reference Waveform Example

Next, we can see that we have narrowed it down to one 720-degree event. But as we see, the pressure wave-
form signatures do not line up due to the timing at which they operated in the engine.

62
 Introduction to PicoScope 7

Make a Reference Waveform & Measure Delay/Advance

The next step is to create a reference waveform from one of the waveforms. In this case, we selected GREEN, channel C.
We then remove the real channel C from view and leave only the reference waveform titled: C number two. Next, we will
use vertical cursors to measure the amount of advance or delay that we need to move our reference waveform to achieve
our proper overlay. In this case, the amount of adjustment is 19.18 milliseconds. By utilizing a positive or negative suffix,
it will determine whether the waveform is advanced or delayed on the screen, as seen in the next picture.

Create a reference
C(2)

Delay

Advance/Delay Cursor Value

63
 Removal of Unnecessary Channel Views

Here we have utilized the views button to remove all unnecessary channels.

Views

Advance/Delay Options

64
 Introduction to PicoScope 7

Here are the results after moving the reference waveform the perfect amount of time and we can see a beautiful
overlay of these two cylinders. Although this is beyond the scope of the class, there is an issue with the exhaust
camshaft lobe between the two cylinders and a difference in overall compression of approximately 10 psi.

Vertical Zoom in for Valve Details

We are now utilizing vertical enhancement (x5) to really bring out the differences in the valve operating events.

Custom Probes

Using the custom probes feature allows us to add any other probes from any third-par-
ty manufacturer such as current probes, secondary probes, etc . It also allows us to
change the range of the probes we already have, which in some cases like a capacitive
probe for ignition, we may need to change the range due to inverted views.

The add a probe function in PicoScope 7 is easier than in

Pico 6. When in the channel options menu,
under the probe selection located at the
bottom, we can either add a probe or
edit a probe in manage probes. It is a
user-friendly way to accomplish either
task. In this case, we have decided to
edit a low amp current probe which is
a common 3rd party addition.

65
 Channel options
Probes

Manage probes

Add a probe

Edit probe

66
 Introduction to PicoScope 7

PicoScope 7: Saving a Custom Probe Built in PicoScope 6

We can now see our custom probe is added to the loaded library in our channel A options. In this case, we
are using the K110 microamp probe. With the custom probe loaded, if we click on it, a new icon appears at
the bottom under manage probes called save. Clicking this save button will save the probe and all its settings
into our custom probe library in PicoScope 7.

Custom probe

67
 Custom Probe (K110 Micro Amp) Added & All Range Settings

Now our loaded probe has moved into our custom library with all its attached settings. We can also see that
we can now edit or manipulate it just like any other probe with the edit icon found in manage probes.

68
 Introduction to PicoScope 7

Edit custom probe

Custom probe

Custom K110 Micro Amp Probe in Use

Here is an example of the microamp probe in use in PicoScope 7 looking at a VR/MR style crankshaft posi-
tion sensor on an Audi. As a technician, keep in mind that measuring current in a circuit helps to verify that the
circuit is complete.

69
 Typical Testing Probes

Typical testing probes are basically the same for all lab scopes, in this next section of the class, we talk about
not only the standard Pico probes, but some of the extra accessories/probes that make our jobs utilizing our
lab scope more efficient.

Circuit Voltage Probe Equipment

Here are just a few examples of the items used to

attach to a circuit. We really do have a lot of choices
dependent upon accessibility. Just remember that prob-
ing into a wire will destroy the insulation and may cause
issues if the wire is shielded. Be sure to cover your holes/punctures
with sealers of some type.

Terminal Adapters/Jumpers
Jumper leads or application-specific
adapters can be used to break into the
circuit being tested. This requires the
sensor to be disconnected for installa-
tion of the adapter or jumper wires. It is
important to pay careful attention—if the
circuit has a problem right at that connection,
you may inadvertently fix the problem! As many
of us have experienced, however, that type of fix
usually does not last very long.
Also, a temporary signal loss may result if you are disconnecting a live circuit
which is not recommended. This may possibly set diagnostic trouble codes.
There are many pre-made sensor harnesses available, and many different
sets of jumper wires made specifically for gaining access to a circuit. Used
properly, these test accessories have a very low probability of causing harm
to the circuit or terminals.

AESwave U-Test Kit

The AESwave U-Test kit is a fantastic example of some of the circuit connecting
options that exist.

70
 Introduction to PicoScope 7

Terminal Adapters – Break-Out Style Leads

Here is an example of using jumper wires in

a break-out design to gain access to a MAP
sensor circuit. There are a lot of advantages to
this hook-up. This is great for test driving probe
stability, no piecing, terminal tension (male and
female) and a full circuit inspection depending
upon tools and your hook up habits. This is one
of our favorite types of circuit connection.

The All Familiar Basic x1 Test Leads

When it comes to true voltage penetration of the circuit, we

need to understand the expected value. Depending on the
scope used, the maximum voltage input may be as low as
20 volts or as high as 200 volts. Each scope has a maximum
input value in its specifications or even on the scope box itself.
Some scopes have a dedicated input for things like primary
ignition that can easily exceed 400 volts.

▪ Used to break into a circuit being tested

▪ Lots of choices as to how:
▪ The common lead is used for most voltage testing
▪ Caution must be taken with higher voltage circuits
▪ Understand your scope’s maximum input capabilities

71
 x1 Probe Option Location

Probe location can be found by simply clicking on the channel options box. In this case, we see channels
A, B, C and D. We clicked on the channel A box and opened options. In options, you can see that there are
four options, one of which is probes.

x1 Lead Bad Ground & LIN Bus Example

Power

Shutter control motor

Ground

PCM

72
 Introduction to PicoScope 7

Here is a great example of using all four channels with x1 leads on all. This is a great waveform due to the diag-
nostics that were being performed. This Audi had LIN communication codes for the shutter system in front of the
radiator. So, in a case like this, we would have tested both ends of the LIN bus, one at the shutter control motor
and one at the powertrain control module (PCM). We are seeing this in channel A in BLUE and channel B
in RED. As you can see, they are both identical, meaning the wiring between the PCM and the shutter control
module is complete and representing the same signal.

The LIN bus in this waveform looks fantastic and we do not see anything wrong with it; however, by hooking
to the power and the ground at the shutter control module, power D shown in YELLOW and ground shown
in channel C in GREEN, we can see that channel C ground is lifting to almost a half of a volt. This ended up
being the problem with this car as the ground went to a stud where the nut was loose. So, there was nothing
wrong with the LIN bus, just a bad ground of the module causing the information to be misinterpreted.

Attenuators

When you think you might have a circuit that

requires testing, but it may be beyond the input
voltage limits of your scope, a device called an
attenuator may be used to reduce the voltage so
the scope can safely handle it. Attenuators reduce the
voltage of a signal without distorting its waveform. Typical
attenuators are 10:1, which reduces the input signal
by a factor of ten, or 20:1 which reduce the signal by a
factor of twenty.

Attenuator Location: Found in Channel Options

The attenuator probe option location is found in the channel

options that are available for each one of the available channels, A
through H if using an 8-channel scope, A through D if using a 4-channel scope, etc. No-
tice that the attenuator that is highlighted under the probe heading has an option of 10:1
or 20:1 which are the two basic attenuator values that you will find in your kits. It is also
important to note that under the channel heading, it does indicate that we have selected
the 10:1 attenuator.

Channel options

Attenuator
10:1 or 20:1

73
 20:1 Attenuator Example on Primary Ignition Channel C (GREEN)

Here is a great example of an attenuator in action. Channel C in GREEN in the center of the screen is the
primary ignition signal on the ignition coil of this 1989 Ford F150. It is obviously lacking voltage, as it is only
hitting approximately 90 to 100 volts at times. Although the diagnostics of this vehicle is out of the scope of this
class, you can see the module signal pictured on the top in BLUE channel A and the low amperage current
probe shown on channel D on the bottom of the screen is the ignition coil. You can also see the available
options for a x1 probe with an attenuator installed allowed us to select up to 2.000 volts. We selected the ±
400 volt option.

Obviously, there are some serious problems with the ignition control of this truck and this vehicle was a crank, no
start. The problem was a bad EEC-4 TFI ignition module. The repaired waveform is pictured on the next screen.

Module signal
± 400 volts

Primary ignition

Ignition coil

20:1 Attenuator Example on Channel C Repaired

Now we can see the repaired waveform of this F-150 and a much better control of the ignition coil. The low
current waveform shows beautiful ignition control including the excessive dwell limiting current limiter operating
perfectly. More importantly, we can see the attenuator in full use on channel C in GREEN pegging out at 400
volts. In a situation like this, the ± 400-volt setting was not enough because we were exceeding that value,
and our waveform is clipped on each one of the firing events.

Even with channel C being clipped, we can see that we have much better ignition control. Understand that this is
a true 400 volts. If we allowed this voltage to come in on channel C, it would damage our scope box. Therefore,
the attenuator is necessary and normally is required when scoping primary ignition waveforms.

74
 Introduction to PicoScope 7

60 MHz x10 Passive Probe With Calibration Screw

This is the PICO M1007 passive high imped-

ance probe. It is calibrated to work effectively
with scopes that have an input impedance of
1 MΩ, shunted by 20 pF. You can also use it
with scopes that have an input capacitance
of 10-50 pF. In our experience, it only seems
necessary in the Flex Ray application. Our
leads and scope have no problems until then;
this may not be true for everyone’s equipment.

Anytime you hook a lab scope into a circuit,

your lab scope becomes a part of that circuit
and can cause what we refer to as probe load-
ing. Probe loading is where the scope itself has
an electrical impact on the circuit and can cause issues with the way the circuit operates. This probe allows us
to reduce that probe loading that a normal scope would add to the circuit.

PicoScope 7 Guided Tests Example

Pictured on the following page is an example in the guided test section of PicoScope 7, showing that this probe
is necessary when looking at circuits such as the incredible fast speed of FlexRay of approximately 10 million
bits per second. As mentioned earlier, we personally do not find the need for this probe in most diagnostic cases.

75
 x10 Attenuated Probe Calibration

If a probe of this design is to be used, it is important to realize that it must be calibrated in the x10 setting before
use. There is typically an adjustment screw located either at the probe end or near the connector for the scope.
Most of these probes come with a screwdriver to fit these small holes. In a typical calibration, we will use a known
controlled 1,000 Hertz square wave cycle and adjust the screw until the square wave is perfectly square. In
this screen capture, we have the probe miscalibrated on the top channel A and on the bottom channel B, each
a different direction of calibration. On channel C, we have the probe calibrated correctly.

Calibrated correctly

76
 Introduction to PicoScope 7

Current Probes – Low Amp/Micro Clamps

Current probes, or as we will call them, amp

clamps, seem easy enough to use. You connect
the leads to a scope or DVOM, clamp it to a wire
and you are all set…..right? Many technicians have
trouble at this point and give up. Do not give up,
for once you learn a few simple things about your
clamp, it will unlock a wide variety of useful testing
methods. Tests can include motors, solenoids, most
inputs/outputs. We have built several classes on just
the topic of low amp current ramping alone and it is
a topic that you should study.

Recently, a new player has entered the automotive repair arena: the micro amp clamp. The device can measure
amperage both with alternating current (AC) and direct current (DC). There are several options available,
but they are a bit expensive, typically 600-800 dollars. The specifications for this probe are DC ± 450 mA and
from 0 – 300 mA AC. The uses are a bit limited, but shows great capabil-
ities in the micro amp ranges for things like a variety of input sensors and
communications systems.

PicoScope BNC+ Current Probes

If using BNC+ designed current probes, whether low amp or high amp
on the 4225A and 4425A series scopes, the probe will be self-calibrating
(zeroing) and self-powered through the scope; therefore, no batteries are
necessary. It is also important to realize that when plugging these probes
in, you must pay attention to make sure your Pico software recognized
them properly as a current probe. The scope software automatically
switches to hardware filtering from 20 megahertz to 20 kHz and you
cannot adjust the setting with these probes installed.

Although the Zero is Off a Bit, the Overall Amperage

is the Same

Let’s take a look at the screen capture printed at the top of the following
page. It is just an example of utilizing four different low amp current
probes at the same time. This circuit is a fuel pump circuit off a 2006
Corvette and I'm just using it to show how even different brands of
current probe can show the same quality picture.

Notice that channels A and B options show these as voltage leads

not amperage leads. Both of those probes were Pico PNC+ and the
software did not pick them up properly, yet it did apply the 20 kHz hardware filter, as you can see in the probe
selection box. This is something we have run into on several occasions, and we will just caution you to unhook
your probe and then hook it back up, so it will be picked up properly because otherwise it may not understand
to automatically calibrate zero.

This is also a good screen capture to illustrate the channel labels located on the bottom of the capture where we
have labeled each channel's probe and could add notes if necessary including condition good, bad, and unknown.
77
 Magnification: Zoom in Quality

In this capture, we've just zoomed in to show the quality of each of the probes against each other, once again
very similar in their operation.

Automated Fuel Pump RPM Calculation

Cursor Cursor

8 commutors (revolution)

78
 Introduction to PicoScope 7

By utilizing the cursors, and a little bit of vertical zoom on channel A, you will notice the software automatically
calculated out the time it takes for one revolution (8 commutators) and dictates the RPM of this fuel pump.
These type of calculations save us time, as we used to have to calculate them manually with most scopes.

Current Probes – High Amperage Clamps

Typically, the ranges are from 600 to 2,000 amps in AC

and DC ranges, depending upon applications. There are
several uses for these clamps, but the most common use is
for relative compression and starter/alternator and hybrid/
electric motor testing.

Known Good 8 – Cylinder Relative Cranking

Compression Example

One of the most common uses for a high amperage

current probe and a lab scope is performing a rel-
ative cranking compression test. Once again, we
have written classes on this topic, so the description
of this is a little out of the scope of this class. The
basics are this: every time a piston comes up on the
compression stroke, there is an extra load placed on
the starter, it slows down a little bit and the current climbs.
The idea here, is that the amount of current increase for each
compression stroke should be relatively the same if all the cylinders have the same mechanical compression.

This type of testing, like many others that you will perform with your scope, is only limited by your imagination
and study. In this snapshot, we are not only looking at the relative compression current in BLUE channel A,
but we are also looking at an ignition sync on channel B RED and crankcase pressure through the oil dipstick
tube on channel C GREEN. As noted above, this is a known good reference waveform.

Trigger placement

79
 One last thing to notice in this picture is the placement of the trigger. It appears that the drawing of the waveform,
while it is not accurate as to the trigger placement, but if you look closely, you can see there was some small
noise that the trigger picked up and began drawing in this picture. In most cases, this would not be considered
proper trigger placement, but it worked fine.

Typical Relative Compression With Dead Hole V-8

This snapshot represents one of the more common failures found with a relative cranking compression test. As
you can see in this V8 engine, we have one cylinder which is not producing the correct amount of amperage
when it’s compression stroke has come around. If our sync is on the ignition signal for 1, and the firing order
is 1-8-4-3-6-5-7-2, then our low compression cylinder would be cylinder 3.

8 4 6 5
1 7 2
3

Heavily Filtered/Zoomed 2.7L V-6 Jumped Timing Chain

Here is another view of a relative cranking compression test with a lot of low pass filtering and zoom level increas-
es. This is to show the detail of the unevenness of the compression cycles in this six-cylinder engine. If you look
closely, you can see that there's a rhythmic pattern to where one bank seems to have more compression than
the other bank. This has been a great tool to find issues, like in this case, where the timing chain has jumped.
As you can see with this picture, learning to manipulate your waveforms with filtering and magnification can
yield results that you could not see with other scopes.

80
 Introduction to PicoScope 7

High Current Probe Example: Chrysler 3.6L Pentastar

In this example, we are using a high amperage current probe for relative cranking compression on channel A
in BLUE and ignition sync in RED channel B. We also get the opportunity to see that we have built a custom
probe for this high amperage clamp under the custom column option. Although this is beyond the scope of
this class, we think it's important to realize that having enough information on the screen can be critical. For
example, in this capture, where our compression issue was not happening every 720 degrees. This is definitely
an odd picture for relative cranking compression, but it proves that we must obtain enough detail on the screen
to see the consistency or lack of consistency per each 720 degrees. So, time-based adjustment is going to be
a critical feature for you to practice with and as you can see here, it is set to 10 seconds.

10 seconds

81
 Results From Cylinder #4

In this screen capture, we can see the in-cylinder compression waveform cranking results from cylinder #4. With
practice, it will be pretty easy to see that we have a varying lift issue with the intake valve which will is most likely
due to a combination of a bad camshaft lobe and follower.

High Voltage Differential & Rogowski AC Current Probes

In this example, we are showing an 8 channel PicoScope (4823) with six channels connected using three dif-
ferential probes and three Rogowski AC high amperage current probes.

These Pico TA325 current

probes work great on electric
three phase applications, as
we see in our HEV and EV
vehicles. They are not neces-
sary though, as you will see in
the next screen, where we are
using the Pico TA388 BNC+
high amp probes.

The Pico differential probes

that you see here in YELLOW
allow us to measure up to 700
AC volts and attenuates them
down (10:1 or 100:1), so the
scope channels can handle
them. These are great tools

82
 Introduction to PicoScope 7

for measuring the AC voltage utilized to run HEV and EV electric motors/generators.

The two most common Pico differential probes are:

▪ Pico TA041 ± 700 volts with 10:1 and 100:1

▪ Pico TA057 ± 1,400 volts with 20:1 and 200:1
- This is preferred due to the higher voltage capability

2014 Gen 3 Prius MG2

Here is the current waveform for all three phases of the motor generator 2 (main traction motor) in a 2014 Toyota
Prius while in heavy reverse. You can note in this picture that the current and the phasing of all three are very
even indicating a well controlled electric motor.

All 6 Channels Utilizing the Views Option

Now, if we take a look at the screen capture pictured at the top of the following page, we are seeing another
one of the more button options called views. This allows us to turn on and off particular channels and, in this
case, we have added the other three channels that include the differential probes from our previous capture.
The views option allows users to add spectrum view, scope views, and XY views. These are all advanced
functions that we speak about in our advanced Pico operational class.

83
 Zoomed in for Detail Utilizing the Full Screen Viewing Option

We have now zoomed in to obtain more detail out of the voltage and current control of this known good electric
motor. We are utilizing yet another function found under the more button called full screen. In order to exit full
screen, simply press F11.

Subaru Hybrid With PicoScope TA388 AC/DC Current Probes

Here is an example of using the TA388

high amperage current probes on
a Subaru hybrid. Once again, these
probes are the ones that come in most
of the newer kits including the Pico
high voltage 4425A kit and work well.

OBD II Connector Break-out

Boxes (BOB)

Break-out boxes have d a little pop-

ularity in the past, but they are not
frequently used in shops today. The
concept of a break-out box is that you
can install factory-mated connectors (usually between an electronic control module and its wiring harness) and
have direct access to the circuit through the numbered or labeled test lead connectors on the box itself. This
practically eliminates the possibility of harness or ECM damage from backprobing or wire piercing.

One popular break-out box today is for the OBD II Data Link Connector (DLC). Instead of inserting any sort of
probe into the DLC terminals, you can use a break-out box and practically eliminate the possibility of damaging

84
 Introduction to PicoScope 7

the DLC terminals. If you pay attention to the AESwave

box in the middle picture, you will see a pin 16 on/off
switch. This allows using connector driven scan tools
in the event of circuit issues with the vehicle. Some
boxes utilize LED lights to flicker during voltage tog-
gling communications.

DLC Pins, CAN-C #6, #14 & ISO #7

In this photograph, we are using an OBD-II breakout box

and our lab scope. If you pay attention to the photo, you will
see a very generic OBD-II scan tool hooked up.

Our lab scope is hooked to three different channels con-

sisting of 2 protocols, HS-CAN-C (OEM proprietary) and
ISO-9141(OBD2 Global)
▪ Pin #7
▪ Pin #6
▪ Pin #14

Serial Decoding

Serial decoding is another option found under the more button option and it takes a little bit of practice to use.
However, serial decoding allows us to look at waveforms and see if they are truly decodable into readable data.
In the automotive world, we still have issues with module/data identification because most manufacturers do
not release that proprietary information. Serial decoding in the J1939 world (heavy duty), however, is gaining a
lot of attention due to the ease at which the module and data information is available. The data pictured on the
screen shows the location of serial decoding and the options available within PicoScope 7. This topic is beyond
the scope of this class, but is covered well in both our advanced Pico users and our data communication classes.

Serial decoding

85
 PicoScope 7 CAN-H With Decoding Issues

Now let's take a look at some issues in serial decoding. This message did not decode properly, and a warning
popped up in the middle of the screen stating we may have a sample rate issue. Remember when gathering
waveforms, a good rule of thumb is to capture waveforms at least 10 times the speed of the signal. In high-
speed CAN-C, that runs at 500,000 bits per second. Ten times that rate would be 5 million samples per
second. The samples per second value are in different locations between PicoScope 6 and PicoScope 7. In
PicoScope 6, it can be found under the properties view on the right-hand side of the screen when selected. In
PicoScope 7, we can find it easily in the timebase box in the upper left-hand corner of the screen.

In our picture, the timebase box shows that we are only running 1,000,000 samples per second which is obviously
too slow for a 500,000 bit per second signal. When we zoom into the signal and measure the length of 1 bit, we
can see that the calculation only works out to 313 bits per second. In communication data networks, the time
spacing is incredibly important to properly distinguish the difference between a one or a zero. In this case, the
fix would be to change our sample rate to achieve a faster sample per second. By stepping up to 2.5 million
samples per second, we have made a substantial difference in our baud rate, but it is still a bit too slow at 466
bits per second. This will be a critical measurement when dealing with serial decoding. Keep in mind that in
automotive data networks, we have speeds that range anywhere from around 9,000 bits per second all the way
up to 10 million bits per second and much faster than that in some infotainment systems.

86
Introduction to PicoScope 7

87
 PicoScope 7 Example of What Appears to be a Dirty Waveform
Now we are looking at a high-speed CAN-C network on a General Motors vehicle on the top two channels. They
appear to be wavy and noisy, but are very common to see like this. When we look at the math channel in BLACK
shown on the bottom, we can see our signal has cleaned up substantially and is a good signal for communication.
We have seen much noisier signals that are also considered normal so be careful here.

High speed CAN-C network

High speed CAN-C network

Math channel

GM With Bad Ignition Switch & Utilizing Cursors & Math Channels
We obviously have some communication issues going on here, but surprisingly enough during some of it, the
math channel operation looks OK. We should be able to see that towards the right-hand side of the screen, it is
quite corrupt and repetitive. Notice that we are using two math channels in this instance.
88
 Introduction to PicoScope 7

High speed CAN-C network

High speed CAN-C network

Math channel

Math channel

1999 Jaguar No-Communication Example

Here is an example of a vehicle with no communication on a CAN-C network. We are utilizing both math chan-
nels and serial decoding all at once on this screen. On our A+B math channel in BLACK it is simple to see
that it is not maintaining the close to five solid volts we like to see during normal communications. However, in
our A - B math channel, we see what appears to be good looking communication. The serial decoding on the
other hand is errored out all the way through. The interesting thing about the serial decoding values is every
message is decoded the same way and is repeating the same message repeatedly. We have seen this in many
instances where a module has a bad power or ground and hogs the network with gibberish. In this case, it was
a bad power supply to the instrument cluster.

89
 A + B math channel

A – B math channel

A + B math channel

A – B math channel

Ignition/Sync/COP Capacitive Probes

Ignition secondary, or capacitive probes pick up an ignition secondary signal

by simply clamping/resting onto a spark plug wire. For vehicles equipped with
coil-on-plug ignition, you may need to install test plug wires (pictured in the
lower right-side photograph) to use the probe. One great feature of this style of
probe is that the high voltage that they measure does not come directly into the
test equipment, eliminating the need for attenuation adaptors.

These probes are fantastic, but depending upon the design and insulation of the
vehicle's coils, it can sometimes be a bit of a challenge to obtain a recognizable
signal and then to understand what you see. Sometimes all we need is a sync
for testing purposes, so they are great for that regardless of the type/brand.

90
 Introduction to PicoScope 7

Secondary Ignition Example

Sometimes it is difficult to obtain clean sec-

ondary ignition waveforms off our vehicles
usually due to the design of the ignition sys-
tem. Here is a nice view, zoomed in the burn
time on a BMW secondary ignition taken with
a capacitive probe.

Ultrasonic Parking Sensor & Keyless Entry Test Probes

TA329
The TA329 and TA33 are two of the more obscure probes that have
been offered by Pico for years, maybe the better part of a decade.
They allow us to look at the invisible signals produced from ultra-
sonic parking sensors and keyless entry oscillators. They are
great tools in that they allow us to see if a signal truly exists
and how far out the signal can be transmitted. These will take
some practice to understand, but they are great additions to TA330
your PicoScope.

91
 TA329 Ultrasonic Back-up Sensor Probe

Here is a captured waveform obtained from an ultrasonic backup sensor with the vehicle in reverse. We have
altered the distance a couple inches away from the sensor which obviously changes the amplitude. Even though
this probe will not pick up the full range of a real backup sensor, you can still compare all the sensors against
each other for amplitude and capabilities based off simply a couple inches.

TA329 Magnification Zoom on 1 Event

92
 Introduction to PicoScope 7

On the bottom of the opposite page, we can see a magnification of just one event showing the ringing of the signal.
We should state at this point that this vehicle sends out its pulses in series of two, so this is just one of a pair.

TA330 Keyless Entry Carrier Signal Detector With No Key Presence

When using the TA330 keyless entry carrier signal detector, we can see that the vehicle is searching for a
key even when no key is anywhere near the vehicle. That is what we see in this picture. This picture is taken at
the driver's door handle of a 2018 Toyota Camry and is considered normal.

TA330 Keyless Entry Carrier Signal Detector With No Key Presence

This is a capture with deeper zoom magnification of the same signal with no key present.

93
 TA330 Keyless Entry Carrier Signal Detector With Key Presence

This is the same 2018 Toyota Camry, however, now we have the proper key presence, and you can see that the
waveform has changed quite dramatically.

Key Signal With Math Channel Frequency

This is the same signal with an added map channel of the frequency counter on channel A.

94
 Introduction to PicoScope 7

Deep Zoom of 1 Event for Detail

This is a capture with deep magnification of only one pulse of our key communication with our vehicle. Once
again, this is all known normal.

Pico TA432 Resistance Test Lead for BNC+

The Pico Resistance Test Lead for BNC+. This probe can measure
resistance and includes a diode test function. It is designed to use with
unpowered circuits as it provides its own current source via the BNC+
connection. As with other BNC+ probes, it will self-configure upon plug-
ging it in. It basically performs like the ohmmeter in your DVOM.

Types Of Pressure Transducers

Pressure transducer testing has become an incred-

ible resource for all sorts of testing. We can directly
measure absolute positive/negative pressures whether
hydraulic or gaseous/air. We can measure delta or
changing/pulsing pressures as well.

The accessories, some of which are pictured here,

provide us the ability to not only see the true numeric
value (like a gauge), but we can draw pictures of every
minuscule pressure change to obtain the full picture of
what is truly happening. Like other topics that have been
covered in this class, this is another topic that has entire
95
 classes written about it in our lineup, so please take the time to study those other classes.

WPS500x Example 2010 Dodge Charger Cylinder #4

We are going to use a case study obtained from a 2010 Dodge Charger equipped
with a 5.7L Hemi engine. This screen capture was taken off cylinder #4 as an
in-cylinder compression waveform example utilizing the WPS500x absolute pres-
sure transducer.

WPS500x Example 2010 Dodge Charger Cylinder #6

96
 Introduction to PicoScope 7

This waveform was captured from the same vehicle, but here we are looking at cylinder #6. What we are do-
ing here is taking what we believe is a bad cylinder and comparing it to a presumed good cylinder. There is an
incredible amount of detail to be learned by examining and reading in cylinder compression waveforms. One of
the first things you can do to get started and be accurate is to properly capture your waveforms, properly use
zoom to magnify what you see, and then overlay one a top the other for comparison against each other. This is
the easiest method to get started without being overburdened by the massive amount of measuring points that
are involved in these waveforms.

Vertical Scaling & Offset Options

Now, we are showing the vertical scaling option available in PicoScope 7 by opening our channel options
and the going to the display button. We can adjust our vertical scaling and are offset as seen in this capture.

Channel
Vertical scaling Display

Cylinder #4 Zoom

The zoom box, is

usually found under
the small magnifying
glass, typically posi-
tioned in the upper
right-hand corner of Zoom
your display screen.
This feature helps
users utilize different
types of magnifica-
tion to open up and
stretch our wave-
form to whatever we
decide. This screen
capture is displaying
cylinder #4.

97
 Cylinder #6 Zoom

This screen capture is displaying magnification of cylinder #6. This is the cylinder that we are presuming is bad.

Microsoft Pressure Waveform Overlays Example

98
 Introduction to PicoScope 7

There is a free program called: Pressure Waveform Overlays that is available in the Microsoft App Store.
Download the app and practice with it. This app allows us to overlay one waveform or more over another to
look for inconsistencies in our patterns. This can be camshaft or crankshaft sensor pressure waveforms. There
are unlimited options. If you look closely at this picture, you will see that our two waveforms do not identically
overlay and there is a significant issue on the exhaust opening of cylinder #4. Once again, this technique is
going to take some practice to learn, but it is well worth the time.

This is a Known Good Overlay From 5 Cylinders on a Volvo

99
 This is an example of what a good cylinder to cylinder overlay looks like on this five-cylinder Volvo shown in
this screen capture. It may be hard to tell, but we are literally overlaying all five cylinders on top of each other to
show just how exact the breathing should be from cylinder to cylinder on most vehicles. So, if you compare this
to the previous screen capture where we are displaying cylinders four and six on the Chrysler, you can definitely
see the differences in breathing as compared to this Volvo.

So, Where is the Rest of the Camshaft/Lifter

This is a photograph of a camshaft and lifter that was re-

moved from a 2010 Chrysler equipped with a 5.7L Hemi
engine. It should be relatively obvious that we have an issue
here with the exhaust camshaft and lifter. The question now
is where is the rest of the camshaft and the lifter?

Here is at Least Some of the Camshaft

In this case, some of the metal has stuck to the multiple

cylinder displacement (MDS) solenoid’s permanent
magnet.

Chrysler does have a Technical Service Bulletin (Case

Number: S1709000010 Rev. A) with a release date:
01/16/2021 regarding this problem The issue calls for full
engine replacement due to the lingering effects of the metal,
so be careful.

PicoScope 7: Phase Rulers Example

Phase rulers in PicoScope 7 are found in the rulers menu. At this point in time, it uses colors to distinguish
the phase rulers and has a maximum partition rate of 12 units (2 more than 6). It utilizes the wrap in the same
way that we find in PicoScope 6. With a little bit of practice, this is a straightforward tool.

Rulers

Phase rulers

100
 Introduction to PicoScope 7

Capturing 30 to 50 Point A Compression Peaks is Important

Capturing enough data is one of the downfalls that we see with many new scope and even seasoned scope
users. For an example, we are going to use an in-cylinder compression waveform again as are example.
We like to see 30 to 50 complete events which means we need a time base that is going to cover our needs. In
this picture of an idling compression waveform, we have a time base of 10 seconds per screen. This allowed
us to put measurement cursors across the top peaks of the compression strokes in order to verify consistency.
It is also imperative that the RPM of this engine be relatively stable for this type of measurement.

Capturing 30 to 50 Point A Compression Peaks is Important

101
 #8 Exhaust Lifter

Let’s take a look at the answer to the last screen that

we viewed. In this engine, a small flat spot on the
roller of a lifter can cause the inconsistencies in peak
compression and is very common in some engines
especially the LS series by GM and the Hemi series
by Chrysler. There really is no other conventional test
method that would have found this minor issue. And
this issue would not have been seen if the time-based
chosen did not provide us enough total events.

2012 Jeep Liberty 3.7L Example P0304

One of the questions that we get asked is about intermittent issues and testing techniques. Intermittent
problems can be very difficult to find. Yet in some cases, the problem seems intermittent to us for symptom
diagnostics. If the symptom isn’t there, we can’t find it. That is not completely true. Some of the tests that we
perform can leave small clues as to where errors may exist.

We stated earlier that when capturing in-cylinder waveforms that we should be trying to capture 30–50-point
As. In many cases, longer capture times like these help with overall diagnostics. This includes many different
circuit tests. We have a 2012 Jeep equipped with a 3.7 L engine, it has DTC P0304, but it appears to run great.
You may notice a couple of small inconsistencies on cylinder 4, they are at ~6.5 seconds and again at 14.5
seconds. We will zoom in on them shortly for a closer look.

102
 Introduction to PicoScope 7

2012 Jeep Liberty 3.7L Example, Horizontal Zoom

In this screen capture, we can see one of them at approximately the middle of the screen.

2012 Jeep Liberty 3.7L, Single Event With Issue

Here we have zoomed in on one of our event anomalies. It is quite plain to see here that the intake did not open
properly, and the leaning tower is created by a volume leak. Once again, these tests will let us know early in
our diagnostic routine if simple tune-up related repairs are going to repair our issues.

103
 Utilizing the free Microsoft app called: Pressure Waveform Overlays, we have superimposed cylinders 1 and
5 (bank 1 and bank 2). The software requires a bit of practice, but works great. As of the writing of this class, it
is still available but appears to only work on Window 10/11.

In our overlay, we can easily see that the exhaust ramp and intake ramp are in different locations indicating that
cam timing is off bank-to-bank. We can also easily see that the exhaust plateau shows even and good exhaust
pressure on each side. Keep in mind that not all engines can/will set CKP/CMP correlation codes. This one only
has 1 camshaft sensor.

104
 Introduction to PicoScope 7

Subaru Head Gasket Inspection

As stated before, we are not diving into pressure

waveform analysis as a single topic in this class
and it's going to require quite a bit of study time
on your part, We are just trying to open your mind
to some other possibilities that your scope has. In
this case, we are going to use our PicoScope to
look at the pressure in the cooling system to try
to determine if a compression leak is present. We
can tell you right now that this is a very difficult
type of testing to get a handle on and the results
can be quite varied from awesome to inconsistent,
so you need to be careful when taking these tests
as to what you are seeing.

Cooling System Pressure, Ignition Sync & Relative Compression

Here's an example of an awesome waveform taken off a Subaru that did have a head gasket issue. We can see
a relative cranking compression test and trigger properly setup on channel A and BLUE. We have an ignition
sync on channel B in RED and we have our pressure transducer hooked to the cooling system on channel C
in GREEN. All of this is done during a cranking relative compression test to see the buildup in pressure as we
realize our cooling system issue is coming from a cylinder's compression stroke. If we are synced to cylinder
#2 and our firing order is 1-3-2-4, this would represent cylinder #3

Pressure transducer

Phase rulers

Ignition sync

105
 2001 7.3L PowerStroke Probe Hook-up

Here is a photograph of approach setup on a 7.3L Ford PowerStroke engine. If you look closely, you will see
that we are going to perform a relative cranking compression test and oil dipstick crankcase pressure test
at the same time.

2001 7.3L Powerstroke Relative Compression & Oil Dipstick

Here are the results of that test with the cranking relative compression shown in BLUE channel A and the
crankcase pressure shown in RED on channel B.

Cranking relative compression

Crankcase pressure

106
 Introduction to PicoScope 7

Lots of Filter & a Little Bit of Zoom for Cleanliness

One of the really cool features of Pico is our ability to utilize massive low pass filters and massive amounts of
zoom to clean up our waveforms into clean and legible customer friendly pictures. We have done just that on
this Power Stroke engine to truly show that we have low compression on two cylinders with simultaneous bursts
of pressure in the crankcase indicating cylinder sealing issues.

Circuit Testers & Load Devices

This series of courses was never designed to be

a sales pitch, but there are tools that we have
learned to use over the years in conjunction
with our lab scope that have been made our
diagnostic life easier and more efficient. In the
photos picture here, we have listed three of
tools that have proven quite useful: the Power-
Probe, the Pulse Width Modulated Power Pro
and the U-activate relay circuit tester. These
three tools are only a very small sampling of
useful tools available to us as technicians.
However, these are some of the tools we use
in conjuction with our lab scope to test circuits.
As our series continues, you will see tools like
this being utilized in real diagnostic situations.

107
 Signal Generators & Decade Boxes

When dealing with circuit issues, in some cases it is

beneficial to have a signal or waveform generator
that we can use to verify module responses inputs/
outputs and low voltage controls like a 5 volt signal.
We also use signal generators in some cases as
circuit drivers to verify that responding components
work when obtaining the proper signal from com-
ponents such as fuel injectors, solenoids and pulse
width modulated pressure controls, etc. Some lab
scopes have built-in signal or an AWG (arbitrary
waveform generator) that can be used for these
purposes. There are also many standalone options
for this type of testing. One example shared here is
by Ditex, the AutoSim Pro.

We have also included here 2 decade boxes; one is a resis-

tance decade box and the other is a capacitive decade box.
We use these variable
boxes to apply differ-
ent resistance values
into circuits for many
reasons including tem-
perature sensor sim-
ulation and network
diagnostics, etc. In
cases of circuit noise
or unrealistic signals,
we can use variable
capacitance to see if the signal will clean up and fix our problem. This topic like many other topics discussed
in this class is covered in detail in our advanced Pico users class and others.

Variable Circuit Breakers

Here is a great example of how we used third

party testing equipment in conjunction with a Pico
lab scope. Obviously, these are variable circuit
breakers that are typically utilized to help us to
diagnose circuits that are blowing fuses. They are
great tools, however, they only tell us part of the
story. If we add a lab scope here, sometimes it can
provide us with the necessary clues to discover
what part of the circuit is causing our issue.

Blown Fuse Circuit Testing Option With Scope

If you look at the photograph shared here, we placed on the screen, you
should be able to tell that we are using a loop and circuit breaker to be
able to power the circuit of a fuse that blows while simultaneously monitoring
the current that goes through the circuit. This is an incredible setup that we
use on many occasions when dealing with a circuit that blows a fuse that is
either consistent or intermittent. It works for both.
108
 Introduction to PicoScope 7

2009 Mercedes ML350 Blowing Fuse 101 Intermittently

We are going to apply this testing method to a 2009 Mercedes ML350 that blows fuse 101 intermittently. We
will remove fuse 101 and place our test equipment like the previous page in its place. One of the problems that
we had with blown fuses is that some fuses can branch off into many different circuits in the car and finding the
place where a short to ground happens could literally be somewhere between the front bumper and the rear
bumper. What the current probe will do is draw us a picture of how and when the current flows and if it flows
too high, we can see if there's any consistency, rhyme, or reason to what the current is doing. We may even be
able to wiggle the harness and move the car while watching our lab scope to see if we have spikes of current
that were too high, but not long enough to blow the fuse.

109
 Fuse 101 With Circuit Breaker Installed & Current Probe

Here is a great example of where the combination of our circuit breaker, low amperage current probe and
lab scope have shown us where a massive surge in current (approximately 40 amps) has happened on this
car. Now, what we need to do is zoom in on the waveform and see if there's any consistency or rhythm to where
this obvious burst of current happened.

Zoom Functionality Options

110
 Introduction to PicoScope 7

Problem Found

This is awesome because when we zoom in on this picture, we can now see a few more details. When the
current displaying is operating properly, we have a rhythm of injectors of approximately 1 amp each in perfect
rhythm and the higher spikes (approximately 13 amps) are our ignition coils firing in perfect rhythm except we
are missing one. But when our spike of current happens to 40 amps, it is at the exact time that coil should have
been firing which leads us to a coil that's bad and it doesn't blow the fuse until it intermittently tries to fire.

Ignition Coil Blowing the Fuse

Here is our culprit.

111
 PicoScope Diagnostic Software

PicoScope diagnostic software has some automated test platforms that are incredible. We find in the field
that a lot of technicians don't realize the power of the Pico diagnostic software suite. It may only have a few
useful tests, but they are incredible fast and easy to learn. This software is downloaded and updated every time
PicoScope 6 or PicoScope 7 are downloaded or updated.

There are five different tests found in the diagnostic software:

1. Battery test
2. Compression test
3. Cylinder balance
4. Noise, vibration and harshness (NVH), and
5. Prop shaft balancing

Basic instructions and hookup sche-

matics are available in the help menu,
contents and then under each one of Battery test

the five tests also has menu options.

It is important that the hookups are Compression test
identical to the menu. For example,
in this screen capture, it shows x1
Cylinder balance
leads plugged into channel A and
the WPS500X pressure transducer
in channel B. If the results of these NVH

probes are not what the scope box

expects, the test will not continue. Propshaft balancing
With the BNC+ plus design probes,
it's even easier for the software to
understand.

Compression test

112
 Introduction to PicoScope 7

Battery Testing: Set-up & Options

Battery test

The setup for the battery test is basic including two channels: channel A with the X1 test lead for battery
voltage positive and negative and a current probe to monitor cranking and charging amperage. There
is an option available under the option tab for an extended drop test and separation of the battery cable
from the starter motor. This is not necessary for a standard battery charging system check. The instructions
are as follows.

113
 From Pico: found in the connection portion of Help contents for the battery test:

Additional connections for extended drop test

In addition to connecting Channel A and B as described above, Channel C and D must also be con-
nected as follows:

Channel C: Starter motor positive terminal

Using a BNC to 4 mm lead, connect the red 4 mm plug to the positive terminal of the starter motor using
the appropriate clip/connector. This is the terminal that the main positive cable from the battery connects to.

Channel D: Starter motor negative terminal

Using a BNC to 4 mm lead, connect the red 4 mm plug to the negative terminal of the starter motor
using the appropriate clip/connector.

Note: Most modern vehicles don’t have earth cables to the starter motor. In this case connect to one of
the mounting bolts by which the starter motor is attached to the engine or transmission bell housing, as
the starter will earth through to the chassis and/or battery.

This will enable Pico Diagnostics to separate the cable resistance from the starter motor resistance.

All connections must be clean and free from oil, grease, and dirt to ensure the readings are accurate.

Battery & Charging System Testing: Known Good Battery Test

Here are the results from a known good battery test. It is important during the setup, when using this test, that
the voltage type, temperature, cold cranking amps (CCA), and CCA unit be properly entered at the bottom

114
 Introduction to PicoScope 7

of the screen. It is also important to realize at this point, that it is critical for the temperature is accurate, and the
actual temperature of the battery. This has an impact on your test results when analyzed. We can see in the
graph pictured in the top the results of this battery test going from off, all the way through engine cranking,
engine start and alternator charge. Once we press the analyze button, the software will display the results
with color coding and actual values.

Battery test

CCA unit
CCA
Voltage type
Temperature

Battery Test Example: Questionable Results

Here is an example of what we refer to as questionable results showing a YELLOW indicator next to the
alternator ripple or diode operation. It is our recommendation that anytime you receive a questionable result
while performing these automated tests, that you perform a charging system inspection utilizing true lab scope
channels. In a case like this, we would want to use a PicoScope to obtain a true raw waveform of the alternator
diodes to verify the accuracy of this test.

Questionable results

115
 Here is another example of a questionable result. In this case, the data refers to battery state-of charge. This
is a common result when analyzing data. At this point, recharge your battery and reperform all tests up to and
including standard raw data lab scope testing.

Battery needs charging

Relative Cranking Compression Test With Only Battery Voltage

Here are the results of a relative cranking compression test while only utilizing the times one voltage leads.
These results are displayed in percentage of cylinder versus cylinder with the addition of raw data from the
upper left-hand button.

116
 Introduction to PicoScope 7

Raw data

Pico Diagnostics Using a WPS500x Transducer

Here are some test results utilizing the relative cranking compression test
and the WPS500X pressure transducer. This is a great testing method to obtain
printable cranking relative compression test results with our readings in PSI, rather
than in percentages. This test takes approximately 6 seconds of engine cranking to
achieve its results.

The nice thing about this is that this test is performed with voltage instead of amperage, so accessing the
battery is not necessary, as power and ground are available in many locations. The addition of the in-cylinder
pressure transducer allows the software to measure the actual psi of 1 cylinder and then utilizing the bat
117
 tery voltage drops, it calculates the relativity of the other cylinders. The results are quite accurate if the proper
settings are configured. To add the pressure transducer to this test, simply click the pressure button near the
lower left-hand corner of the screen and then configure the menus. Once the test is completed, click on the
display raw data box located in the upper left-hand corner to see the raw data values for channel A and B in
corresponding BLUE and RED.

Raw data

Compression Results Without the Raw Data Display

118
 Introduction to PicoScope 7

Relative Cranking Compression Results With Dead Hole

It should appear obvious that this vehicle has one cylinder that does not have compression whether we are
looking at the bar graph or the voltage drop representation in the raw data. We caution you that although the
software is designed to synchronize our pressure transducer as cylinder 1, it does not always work out that
way. There truly is no synchronization with these tests and we need to utilize firing order to figure out which
cylinder is which. In some cases, however, the math does not seem to work out. So, when faced with a result
like this, it is important to use your lab scope’s raw data to verify true cylinder location.

Raw In-Cylinder Compression Signature Verification

119
 As previously mentioned, it is best practice to follow up any
questionable results found in automated diagnostic software. In
this case, we have now taken our cylinder compression waveform
from our presumed bad cylinder #6. This class was not designed
to be an in-cylinder compression waveform class, but you should
be able to see the obvious variances in overall compression with
this engine at idle. This is typical of roller lifter/camshaft follower
style valvetrain systems that have problems with the roller. These
types of problems are becoming more and more common.

Example: Using Math Channels for the Filter

Although filters can be applied directly to any channel at anytime, here is another example of utilizing filters
and math channels together. When utilizing aggressive filters, whether on a raw channel or a math channel,
we can achieve just about anything.

By utilizing the follow up of a cranking relative compression test because of what we consider to be the ques-
tionable results through Pico diagnostics and filtering our results, we can now see that we have an engine (2.7L
Chrysler V6) that has jumped time. Without following up with a raw cranking relative compression waveform
as we have here, we may not have noticed the difference from bank-to-bank in current flow. It was difficult with
how noisy this starter’s current draw was, and if we did not use filtering techniques, we would not have seen it.

120
Introduction to PicoScope 7

121
122
 Introduction to PicoScope 7

Pico Diagnostics: Power Balance

The cylinder balance feature, utilizes charging system fluctuations to determine power balance. This test can
be a little difficult to set up and functionally, it can yield questionable results with a computer-controlled charging
system. It is a great test and with some practice, it can yield usable results. Both screen captures were obtained
from a 1994 Chevy Silverado equipped with a 5.7 TBI. The first capture shows normal cylinder contribution without
any issues. The second capture shows one noncontributing cylinder. When viewing the raw data, we can see
the seven contributing cylinders in voltage boosts and the lack of one in between. There is no synchronization
in this test, so the results just point out the lack of RPM contribution based off charging system voltage, but not
which cylinder. So once again, conventional style testing would need to follow.
123
 NVH: Frequency, Order, Direction & Force (dB and G)
The basics of automated noise, vibration and harshness (NVH)
testing is simple. The idea here is that if you have a vibration in
a vehicle, it is probably going to be from a rotating component.
These rotating components typically break into three categories:
1.) engines/transmissions, 2.) drivelines, and 3.) wheel/tire/axle
assemblies. Of course, there are others, but they are on the rarer
side of things, and we will discuss those in our class series form
CTI called NVH.

The idea is this: If we have a way to measure how strong the vi-
bration is, which direction the vibration is occurring, and how many
times per second the vibration is shaking, then at this point, we
can match the rotational speed of the vibration, the direction of
the vibration and match it to whatever spinning component on the
vehicle is rotating at the same speed. Most of the equipment that we used can do just that. This is a topic that
requires quite a bit of practice, but if you spend the time to learn it and use good equipment, you will appreciate
the results. With some imagination and understanding of natural vibrations, we can even use these systems to
find rattles, wind noises, etc.

Subaru: Shake in Steering Wheel

Here is a screen capture obtained from a Subaru that had a vibration or shake in the steering wheel. In this screen
capture, we are not demonstrating how to diagnose the vehicle, but we are showing you another option inside
NVH called: unknown vibrations. As mentioned before, NVH diagnostics is a topic all on its own and we at CTI
have an incredible class on just this topic. If you are interested in NVH, then we highly suggest you attend our
NVH class. In this case, the direction of our vibration is lateral, which leads us to believe that we have a beating
coming from side-to-side in this car. We used this to help determine that we had a loose tie rod end. That vibra-
tion did not meet the rotating frequencies of anything else and that's why we found it in unknown vibrations.

124
 Introduction to PicoScope 7

2015 Honda Pilot With Shuttering Torque Converter Clutch

Here is just another picture of using NVH on a 2015 Honda Pilot. This vehicle had a relatively severe shaking
while driving down the road at higher speeds, typically 50 plus miles an hour. Utilizing NVH, we were able to see
that our vibration was quite severe at 50 mgs of force at times and happening once per crankshaft revolution,
typically eliminating other rotating components in the vehicle.

Lab Scope & NVH Pick-ups for Time Domain Noise Location

125
 It can be difficult to determine the source and location of a noise when looking for noises such as a popping,
squeaking, thumping, etc. It is difficult for noises to travel through the air, although we obviously know they
do. However, some materials allowed noises to travel very quickly, and they typically come from the metals that
are utilized to put our vehicles together. When looking for a noise, consider that a noise must start somewhere
and travel through a responding component. The idea here with time domain on a lab scope, is if we use two
sensors to pick up the noise, then the sensor that is closest to the origin of the noise will pick up the noise be-
fore the second sensor. In the data pictured here, we can see a very small time deviation between the upper
waveform and the lower waveform. This indicates that the sensor that was hooked to the upper waveform saw
the noise before the sensor that was connected to the lower sensor, thereby indicating that it was closer in
location to the origin of the noise. With this style of testing, we are not necessarily concerned with the amplitude
of the noise, just who created the noise first.

Optical Sensor Kit Required for Propshaft Balancing Feature

Pico’s Optical Sensor kit is required for propshaft balancing. This software
is designed to utilize different methods of propshaft balancing including the
hose clamp method and the ability to just add weights to things like pinion
flanges. The setup wizard walks users through these different setups. This
system is not limited to just balancing driveshafts, any rotating component
can be balanced using this method with some imagination and setup.
Driveline balancing is by far the most common use for the optical sensor
kit. This can be a great addition to your shop to help diagnose driveline
issues before sending them out for repair or replacing with new units.

This system is used in conjunction with the Pico NVH system and requires
that your scope is already set up (registered) to handle NVH.

Propshaft Balancing Set-Up Wizard

Here are a few screenshots of the propshaft balancing option (there are a lot more). The setup wizard helps
technicians in guiding the setup for this feature. There is also a manual setup procedure for those more familiar
with this equipment. The complete operation of this system is beyond the scope of this class.

126
Introduction to PicoScope 7

127
 Summary

As a new user or experienced PicoScope 6 user, the advantag-

es of PicoScope 7 software is clear. Most functions are now
available within one to two mouse clicks and useable platforms
are now available for both Linux and Mac. This version of Pico’s
software is designed to be used on modern devices such as
touch screen and multi-operation system versions. Specific Pico
probes are available via Pico Technology, but the PicoScope
can also be used with many aftermarket custom probes and
testing tools. Newly designed BNC+ probes are now easily
auto-identified and sample rate settings are easily seen on the
main screen. The Guided test menu has an incredible knowl-
edge base and the Advanced waveform library is growing on
a daily basis. Ease of use combined with advanced features,
and the Pico waveform library ensure that this tool is part of
advancing technology and testing techniques. As it’s been said
in this course, imagination is the only thing holding us back!

128
 Post-test Questions

1. PicoScope 7 must be run on a 64 bit system because of security concerns when using the waveform library.

__________ True __________ False

2. Pico 7’s connect detect feature can be used to verify proper probe connections and can be used with which
of the following probes?
A. X1
B. Current probes
C. Capacitive ignition probes
D. WPS500x pressure transducer
E. All the above

3. Which of the following automotive Pico interfaces have a built-in arbitrary waveform generator?
A. 4423
B. 4425
C. 4425A
D. 4823
E. All the above

4. Pico 7 software includes which channel coupling options? (Circle all that apply.)
A. AC
B. DC
C. Frequency counter
D. All the above

5. The Pico Diagnostic software suite can be used to perform a relative cranking compression test and show
the results in actual psi of pressure for each cylinder of an 8-cylinder engine if an in-cylinder transducer is
utilized on just 1 cylinder during the test.

__________ True __________ False

6. Pico 7 software math channels can be used to graph the frequency (acceleration/deceleration) of a crank-
shaft position sensor signal to aid in misfire diagnostics.

__________ True __________ False

7. The buffer library in Pico 7 is limited to 64 pages maximum.

__________ True __________ False

8. Each scope view in Pico 7 is limited to how many channels when using a 2 channel 4225A?
A. 8 B. 6
C. 4 D. 2

9. A 20 kilohertz hardware filter is a built-in feature in for use in which Pico automotive interfaces? (Circle all
that apply.)
A. 4423 B. 4823
C. 3423 D. 4425
E. 4425A F. 4225

10. Reference waveforms in Pico 7 allows us to overlay known good and bad captures in more than one
scope view at the same time.

__________ True __________ False

 NOTES:

130
 Introduction to PicoScope 7

NOTES:

131
 NOTES:

132
 Please take a few minutes to complete this form.lt is the only way we can make the changes YOU want.
Remember this is your class!

Dates of Class:_________________________ Instructor:___________________________

Class Name:____________________________ Region #:____________________________

Please check the appropriate boxes.

1. Please rate how well the subject matter of this course 6. Please rate the instructor's knowledge of the subject:
met your expectations: Excellent  Good  Fair  Poor 
Excellent  Good  Fair  Poor  7. Please rate the instructor's ability to deliver the subject:
2. Please rate how well this class will help you improve Excellent  Good  Fair  Poor 
your skills: 8. Please rate the instructor's ability to answer questions:
Excellent  Good  Fair  Poor  Excellent  Good  Fair  Poor 
3. Please rate the likelihood that you will apply what you 9. Taking everything into consideration, would you say this
learned back at your shop: class was:
Excellent  Good  Fair  Poor 
4. Please rate the likelihood that you will recommend this Very worthwhile 
class to another technician:
Excellent  Good  Fair  Poor 
Worthwhile 
5. Please rate how well the instructor covered the subject Somewhat Worthwhile 
matter: Not worthwhile 
Excellent  Good  Fair  Poor 

For what other subjects would you like CTI to develop classes?

May we follow up regarding your comments? Yes  No 

(Optional) SS#
Name
Phone
Shop
City

If you would like ASE CASE CEU credit, you must provide your name and SS#.
Comments: