DTC 32

Code 32 Chart:

Code 32 Wiring Diagram:

***UPDATED BY TSB # 90-110-6E DATED DECEMBER 1989

CIRCUIT DESCRIPTION:

The Integrated EGR valve functions similar to a port EGR valve with a remote vacuum regulator. The internal solenoid is normally open, which causes the vacuum signal to be vented off to the atmosphere when EGR is not being commanded by the ECM. This EGR valve has a sealed cap and the solenoid valve opens and closes the vacuum signal which controls the amount of vacuum applied to the diaphragm. The electronic EGR valve contains a voltage regulator which converts the ECM signal to provide different amounts of EGR flow by regulating the current to the solenoid. The ECM controls the EGR flow with a pulse width modulated signal. (This signal turns on and off many times a second) and is based on air flow, TPS and rpm. This system also contains a pintle position sensor which works similar to a sensor, and as EGR flow is increased, the sensor output also increases. Code 32 means there has been a EGR system fault detected. Code 32 will set under two conditions.

^ Coolant temperature above a specified amount, and EGR should be "ON".

^ EGR pintle position does not match duty cycle.

NOTE: Because of all the possible color code combinations used on electrical wiring diagrams, always refer to ECM CONNECTOR IDENTIFICATION under ELECTRICAL AND ELECTRONIC WIRING DIAGRAMS for correct color code identification of circuit.


TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.

1. With the engine running and the transmission in gear, with brakes applied, increasing the engine rpm will put a load on the engine. Engine vacuum will be applied to the EGR diaphragm and cause the EGR pintle to open increasing pintle position voltage.

2. Grounding the diagnostic terminal should energize the internal solenoid which closes off the vent and allows the vacuum to move the diaphragm. This test determines that the ECM is capable of controlling the solenoid. When EGR is commanded on by the ECM, the test light should be "ON."

3. If circuit 450 is open, the pintle signal will go high (showing a 5 volt signal). This will set a Code 32. If circuit 911 becomes shorted to 12 volts or to circuit 474, the signal voltage will go high causing a Code 32.



DIAGNOSTIC AIDS:

Some "Scan" tool will read pintle position in volts. The EGR position voltage can be used to determine that the pintle is moving. When no EGR is commanded (0-% duty cycle), the position should read between 0.5 volts and 1.5 volts and increase with the commanded EGR duty cycle. If the system seems to be operating properly refer to TESTING PROCEDURES/DIAGNOSIS BY SYMPTOM/INTERMITTENTS.