May 2015 - Technical Newsletter

Done Dyna PRO2

This article is a true description of an AECS
technical help desk problem and how it was solved.
SCAN Tool
Vehicle
2000 Toyota Dyna, S05D 4.9 Ltr 4cyl.
engine

Set up to work with

Not many left at this GoLo Car Care
Note:
crazy price of
Comes as an
$2,250 + gst ! optional extra

Features
 Modern Android 7” Touch Screen operating system.

 Wireless Bluetooth communication and diagnostics with

over 74 vehicle brands.
Problem presented to the Helpdesk  12 months of Software Updates included
The truck was referred to the workshop (who owns
 One Touch software upgrades via WiFi. Continuously
AECS diagnostic equipment) by another garage,
evolving software with regular updates!
as they were at the end of their diagnostic ability.
The truck has this complaint, that when the engine  Take screen shots and print live data.
was warm; you could not rev it over around 2500  Individual or Multiple Combined Sensor Graphing.
RPM as it would start to misfire and smoke really
 Auto vehicle recognition.
bad.
The garage who first worked on the truck had  Special Functions including Injector re-coding, throttle
replaced the air cleaner, injectors, injection pump, re-learn, remote key reprogramming + re-pairing, battery
replacement, G-Sensor Zero point calibration, many more.
cleaned the intake manifold and blanked off the
EGR channel. Because there were no fault codes,  Database for wiring diagrams and special diagnostic
they even tried another ECU. procedures specific to certain manufacturers.
All to no avail! I am unsure what the total costs  AECS Technical support available directly through the tool
were but the replacement (new) injection pump by via your wireless network.
itself was around $4500.
What would you do next? Call AECS today:
Diagnose Ph: 06-874-9077
After having the vehicle in their workshop for
months the shop passed the vehicle on to a
Authorised Launch distributor
 workshop who has invested in decent diagnostic The long recording of the spill valve vs pump shaft
equipment. sensor signals (in picture 1) showed erratic run-
We started by measuring the Spill valve vs the ning but no real changes in spill valve actuation.
Timing control valve (TCV) on the pump. Bad This ruled out that quantity changes were the
running could be caused by incorrect quantity (spill cause of the erratic running.
valve) or incorrect timing (TCV). It was immediately
evident that the TCV signal was erratic when the TCV
The same recording was done with the TCV in
truck misfired.
picture 2.
The misfiring only happened when the engine was
hot, so not to have to wait till the engine was warm
all the time we fitted a variable resistor in place of
the coolant temp sensor. We could ‘turn the bad
running on/off’ by changing the temperature signal.

At this stage most technicians would call it a day

and fit a resistor in the coolant temp circuit. In our
feeling there was more to this story so it is better to
investigate properly.
Picture 2: Zoomed in on ATS 500XM scope recording
of TCV vs Pump shaft sensor when the engine is
misfiring badly.

The recording was made using split screen, so

we could investigate the raw signal and the calcu-
lated signals in separate screens.
The first screen shows the simple recorded
patterns of the TCV and the pump shaft, zoomed
Picture 1: ATS 500XM 2 channel scope recording of in on one area of interest.
Spill valve vs pump shaft sensor The second screen shows the TCV’s duty cycle
and the pump shaft sensor’s calculated speed
transformed into two analogue patterns.
It is clearly visible that the RPM is not steady
Scan tool
(misfiring) and that the timing control valve makes
PRO3 very big changes to correct the injection timing.
$4,099 +gst
AECS technical support included To me this looks like the problem!
Authorised Launch distributor
Investigate why
 Modern Android OS, 10.1” Touch Screen To find why the engine is running bad is one thing
 Wireless Bluetooth communication and diagnostics with over 74 vehicle brands
but now we had to find out why the ECU was
 12 months of Software Updates included
 One Touch software upgrades via WiFi. Continuously evolving software with daily updates correcting the timing so violently, causing misfires
 Take screen shots and print live data on the way.
 Individual or Multiple Combined Sensor Graphing
 Automatic vehicle recognition
 Up to 15 life data graphs.
Firstly see what the pattern looks like when the
 Full day’s work worth of battery life engine is running fine, by dialling up a cold
 Special Functions including Injector re-coding, throttle re-learn, remote key reprogram- engine temperature (Picture 3). The setup was
ming plus re-pairing, 12v battery coding, G-Sensor Zero point calibration, & many more
functions TCV vs TCV current, so we could in the same
Ask for our scan tool comparison chart
measurement eliminate any bad connections in
PLUS
AECS Online technical the TCV circuit.
support available
directly through the tool!
 Complete Kit
Diagnostics
$12,000+gst
and very complete Note: pricing depends on options and
database for extras

Truck, Trailer, bus,

light commercial
and agricultural
vehicles

Ring 06-874-9077
for more information www.aecs.net

connection in the TCV circuit. One moment it is work-

ing properly, then the next moment it lets go. When
the connection is lost the valve will close, advancing
the timing, even though the ECU is trying to retard, by
increasing the duty cycle. The next moment the con-
nection is ‘made’ and a far too large duty cycle open-
ing the TCV fully retarding the injection timing too
much. We have dealt with a number of cases doing
just that at the AECS help desk.
Picture 3: ATS scope recording of TCV voltage over
current, running good (cold engine).

Picture 5: Zoomed in portion of TCV recording.

Picture 4: TCV voltage over current, running really By zooming in on a portion of the pattern (Picture 5)
bad (warm engine).
where the duty cycle changes are ‘violent’, we saw
Zoomed in we could see if the current was as ex- no changes in current. We expected to see a sudden
pected or perhaps the cause of the erratic running. drop to zero amps, just before the duty cycle went
What was in our minds was for example a broken up.
pin in the TCV connector making and breaking a We were wrong.
 What’s next?
We started to doubt, the TCV duty cycle fluctua-
AECS 2015 training: tions might have been normal, we had no vehicle
to compare. We looked in more detail at the spill
Enclosed is a quick view of our 2 Day training courses
valve vs pump shaft to see if there were any minor
for 2015. Enrolling early ensures you secure your
changes in injection volume or Spill valve timing,
place on our popular training courses.
no changes.
ECAC1 - Air-conditioning
8 - 9 June 2015 - Christchurch What was evident from the spill valve/ pump shaft
2 - 3 July 2015 - Hamilton speed sensor recording was that every beat there
8 - 9 September 2015 - Whangarei were large speed fluctuations. We explained that
19 - 20 October 2015 - Auckland as the cam in the pump ‘flicking’ past the top dead
centre (climbing the cam vs falling).
AED - Automotive Electronic Diagnostics
5 - 6 May 2015 - Auckland FULL
8 - 9 June 2015 - Christchurch 1 Spot left !
23 - 24 June 2015 - Rotorua
13 - 14 July 2015 - New Plymouth
7 - 8 September 2015 - Hamilton

EMS1-1 Engine Management Systems

15 - 16 October 2015 - Auckland

EMS1-3 Engine Management Systems

23 - 24 July 2015 - Auckland

EMS1-5 Immobiliser & Anti theft devices

10 - 11 June 2015 - Christchurch
Picture 6:Detail of spill vs pump shaft recording
SCAN1 - Scan tool Diagnostics
Could there be mechanical damage inside the
25 - 26 June 2015 - Hamilton
new pump, that free play allowed the pump shaft
13 - 14 October 2015 - Auckland to speed up/slow down out of synch with the crank
shaft?
FULL
DMS1-3 Common Rail Diesel Systems It was a long shot but a simple pump vs crank-
5 - 6 May 2015 - Auckland shaft sensor recording was made to confirm:

CANBus 1 4 hrs ($155+gst)

6 June 2015 - Christchurch 1 Spot left !
18 June 2015 - Hastings
17 July 2015 - Palmerston North
11 September 2015 - Taupo
3 October 2015 - Auckland

Ph:06-874 9077 www.aecs.net

NB: Course dates subject to change, please

check our website for current course dates. Picture 7: Split screen recording ATS 500XM of Pump
shaft vs crank shaft sensor, when running bad.
The relation between the pump and crank shaft
signals showed hardly any movement (maximum of
0.5 pump shaft teeth) when the vehicle was
running bad! Again the doubt set in. Was this a
timing issue?
Yes the ECU could perhaps keep the timing
virtually correct by its violent duty cycle swings, but
then you have to consider that the crank/pump
shaft recording showed the outcome of the timing
corrections, so the engine should be running
correct….. That is a brain teaser aye?
Consider that the crank shaft has got only one lobe
(pulse) per revolution, how precise can the timing
be corrected when you only once per revolution Picture 9: Badly worn idler gear, from the pump and
check the pump position, while correction takes camshaft drive train

place continuously?
To make sure that our forming thoughts were
correct, we checked the ECT, MAP and APS
AECS Equipment
sensor when it was running badly, to see if those
signals were perhaps erratic causing the timing
changes, all measured stable.

Timing corrections
Pump timing correction is a function of pump
sensor speed changes (time) and phase difference Professional 500 MS/s 14-bit dual channel High
between the pump and crank shaft signals. Resolution Oscilloscope with signal generator.
Now put that into perspective with the speed
fluctuations every time the cam lobe in the pump Scope
‘flicks’ past TDC. Full kit:
$7,700+gst
Free play
After this conclusion the diagnostician decided that Scope Only:
it was time to see if there was any free play in the $3,840+gst
pump drive train or in the pump itself.
Lifting the rocker cover revealed a badly worn cam
gear. Removing the gearbox and cam drive gear
cover, revealed a mess. This powerful high speed USB oscilloscope features:
- fast sampling up to 500 Million Samples/sec
- high resolutions of 12, 14 and 16 bit,
- a large memory (buffer) of 64 Million Samples .
- an extremely accurate built-in 30 MHz 14 bit arbitrary
waveform generator (signal generator).

The oscilloscope supports continuous streaming

measurements up to 20 MS/s and can be synchronized
with other oscilloscopes to form a multi channel
combined instrument with synchronized time-base.

The flexibility and quality that the ATS 500XM offers is

unparalleled by any other oscilloscope in its class.

Picture 8: Denso pump (picture from internet)

Metal filings were found in the oil filter indicating
that not just the drive train was worn but that most BRAKE TESTERS for Light
likely oil galleries, oil filter bypass valve, piston
cooler pipes, etc. were all full of filings as well. The
& Heavy
engine was done!
The brand new pump was left alone, as that would
Vehicles
be the least likely have internal free play.
A decision was made to replace the engine for a
second hand unit.

Right from the first beat the replacement engine

was running perfect.
From $22,500
Conclusion + gst
Imagine that the diagnostician put a resistor in the
VTEQ 3080 HD
coolant temperature circuit? Who would have
gotten the blame for this engine blowing up. I can COF-B certified (limited)
see the customer relating the colder temperature 12kn per wheel, 4x4 brake tester with digital
setting (as a result of the resistor) to advanced display cabinet. Includes printer, remote control,
timing, knock and engine damage. weight cells, cover plates, Wi-Fi & networking.
AECS is accredited by the NZ Transport Agency to
Also the cooling fan would not have come on or too deliver certified roller brake machine training for
late, resulting in engine damage in the mind of the COF - B Vehicle Inspectors.

customer. Call us for training dates

Who would they have blamed for breaking this
already ‘broken’ engine?? AECS Equipment
www.aecs.net
PH:06-874 9077
This problem was not easy to find, simply because
it is hard to find a mechanical fault with a scope.
Also the judgement call to go after the free play
(cam flicking), was not easy to make. Yet I can say “Calling all ATIS scope users !”
that I have never seen speed changes as bad as in This course is specifically designed for the scope you have
the recordings made in this article. and will train you and your staff up in how to get the most
out this nice piece of equipment, along with learning new
How would you have solved this issue? diagnostic methods.
After having replaced everything including the It also covers the specific features of the ATIS v5 software in
engine you would have gotten there! Is that depth, for example RPM, Duty cycle, injection volume and
signal generator.
realistic?
Please consider quality equipment which has the
abilities needed out there! 11th & 12th May 2015 - AUCKLAND
I see too many times that scopes are sold into 4th & 5th June 2015 - CHRISTCHURCH
workshops with the following line: “a scope is a 15th & 16th July 2015 NEW PLYMOUTH
scope”.

That is not true! That is only people speaking Ph:06-874 9077

without technical knowledge, pushing a sale. or email

Training@aecs.net

For AECS Ltd

Herbert Leijen
06 8749 077 AECS training relevant to your workshop.
www.aecs.net