Scribd
Upload
1K views2 pages

Toyota Corolla G & NE Signal Circuit Fix

This document provides troubleshooting steps for resolving a code 12 error related to the G and NE signal circuits in a 1995 Toyota Corolla 1.8L engine. The error occurs when there is no NE signal to the ECM within 2 seconds of cranking or no G signal for over 3 seconds between 600-4000 RPM. The diagnostic procedure involves checking resistance readings of the distributor pick-up coils, inspecting circuits for opens or shorts, and measuring the air gap between the pick-up coils and rotor if resistance readings are normal. Replacing the distributor or ECM may be required depending on the test results.

Uploaded by

Bruce Lynde
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
1K views2 pages

Toyota Corolla G & NE Signal Circuit Fix

This document provides troubleshooting steps for resolving a code 12 error related to the G and NE signal circuits in a 1995 Toyota Corolla 1.8L engine. The error occurs when there is no NE signal to the ECM within 2 seconds of cranking or no G signal for over 3 seconds between 600-4000 RPM. The diagnostic procedure involves checking resistance readings of the distributor pick-up coils, inspecting circuits for opens or shorts, and measuring the air gap between the pick-up coils and rotor if resistance readings are normal. Replacing the distributor or ECM may be required depending on the test results.

Uploaded by

Bruce Lynde
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 2

7/29/2015 Printer Friendly View

1995 Toyota Corolla 1.8L Eng DX

CODE 12 - G & NE SIGNAL CIRCUIT (NO. 1)

CAUTION: If ECM replacement is instructed in following testing, always ensure


ECM harness connector and ground circuit are okay. If either are suspect, repair and
repeat testing to confirm ECM malfunction.

Circuit Description

The distributor or Integrated Ignition Assembly (IIA) contains 2 pick-up coils and G and NE signal
coils. The G signal pick-up coil sends the ECM standard crankshaft angle. The NE signal pick-up
coil sends the ECM crankshaft angle and engine speed. Code is set when there is no NE signal
to ECM within 2 seconds after cranking and/or no G signal to ECM for 3 seconds or more with
engine speed of 600-4000 RPM. Possible causes are:

G and NE open or short circuit.

Distributor pick-up coil(s).

STA open or short circuit.

ECM.

Diagnosis & Repair

1. Ensure ignition is off. Disconnect distributor 6-pin connector. Using ohmmeter,


measure resistance between specified terminals. See Fig 1 . See G & NE PICK-UP
COIL RESISTANCE table. If an y resistance measurement is not within specification,
replace distributor. If all measurements are within specification, go to next step.
G & NE PICK-UP COIL RESISTANCE

Terminals Ohms

Cold (1)

G+ & G- 185-275

NE+ & NE- 370-550

Hot (2)

G+ & G- 240-325

NE+ & NE- 475-650

(1) Temperature range of 14-122°F (-10-50°C)


(2) Temperature range of 122-212°F (50-100°C)

2. Inspect circuits between distributor and ECM for open or shorts. See wiring diagram in

http://www1.prodemand.com/Print/Index?content=article&module=false&tab=false&terms=false 1/2
7/29/2015 Printer Friendly View

the WIRING DIAGRAMS - 1.6L article. Repair as needed. If all circuits are okay, inspect
air gap between each pick-up and signal rotor. See the REMOVE/INSTALL/OVERHAUL
article.

3. If either air gap is NOT within specification, replace distributor. If both air gaps are
within specification, replace ECM and retest.

Fig 1: Identifying Distributor Connector Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

http://www1.prodemand.com/Print/Index?content=article&module=false&tab=false&terms=false 2/2

You might also like