DTC 32

Exhaust Gas Recirculation (EGR) Circuit:

CIRCUIT DESCRIPTION
The integrated electronic Exhaust Gas Recirculation (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 Electronic Control Module (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 integrated 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, Throttle Position Sensor (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.

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

1. Whenever the solenoid is de-energized, the solenoid valve should be closed which should not allow the vacuum to move the EGR diaphragm, However, if the filter is plugged, the vacuum applied with the hand held vacuum pump will cause the diaphragm to move because the vacuum will not be vented to the atmosphere.
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 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 357 becomes shorted to 12 volts or to circuit 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 (0-% duty cycle), the position sensor should read between (0.5 volt and 1.5 volts) and increase with the commanded EGR duty cycle.

Refer to Diagnosis by Symptom / Intermittents. - Intermittent Malfunctions