Turbo

Code 32 Chart:

Code 32 Wiring Diagram:

CIRCUIT DESCRIPTION:

The integrated electronic EGR valve functions similar to a port 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 vented to atmosphere, and this 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 EGR flow with a pulse width modulated signal (turns "ON" and "OFF" many times a second) based on air flow, TPS, and rpm.

This system also contains a pintle position sensor which works similar to a TPS sensor, and as EGR flow is increased, the sensor output also increases. Code 32 means that there has been an EGR system fault detected.

Code 32 will set under two conditions:

^ Coolant temperature above a specific amount, 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 engine speed 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 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 the EGR is commanded on by the ECM, the test light should be "ON".

3. If CKT 452 is open, the pintle signal will go high (showing a 5 volts signal). This will set a Code 32. If CKT 357 becomes shorted to 12 volts or to CKT 416, the signal voltage will go high causing a Code 32.



DIAGNOSTIC AIDS:

Some "Scan" tools 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 (O% duty cycle), the position sensor should read between 0.5 volt and 1.5 volts and increase with the commanded EGR duty cycle if the system operates correctly. Refer to TESTING PROCEDURES/DIAGNOSIS BY SYMPTOM/INTERMITTENTS.