DTC 32

Exhaust Gas Recirculation (EGR) Circuit:

Circuit Description
The PCM operates a solenoid to control the Exhaust Gas Recirculation (EGR) valve. This solenoid is normally closed. By providing a ground path, the PCM energizes the solenoid which then allows vacuum to pass to the EGR valve.

The PCM monitors EGR effectiveness by de-energizing the EGR control solenoid, thereby, shutting "OFF" vacuum to the EGR valve diaphragm. With the EGR valve closed, and 025 fluctuating normally, fuel integrator counts will be greater than they were during normal EGR operation. if the change is not within the calibrated window, after failing the test twice a DTC 32 will be set.

DTC 32 Will Set When
^ Throttle position between 5% and 40% angle.
^ Steady throttle with no more then 2% change in throttle.
^ Above 35 mph "Closed Loop" operation.
^ Max short term fuel trim less then 8 counts for 2.5 seconds.
^ Desired EGR command greater then than 50%.
^ MAP above 55 kPa or less then 20 kPa.

Action Taken (PCM will default to)
The PCM will turn "ON" the MIL (Malfunction Indicator Lamp).

DTC 32 Will Clear When
Conditions for fault are no longer present and Tech 1 "Clear DTCs" function is used or 50 ignition switch key cycles have passed with no further faults or ignition switch is turned "OFF" and fuse #9 (ECM B) fuse is removed for 10 seconds.

DTC Chart Test Description
Number(s) below refer to circled number(s) on the diagnostic chart.

1. By commanding the EGR solenoid "ON," vacuum is applied to the EGR valve and the vacuum should hold.

2. When the diagnostic terminal is ungrounded, the vacuum to the EGR valve should bleed off through a vent in the solenoid and the valve should close. The gage may or may not bleed off but this does not indicate a problem.

3. This test will determine if the electrical control part of the system is at fault or if the connector or solenoid is at fault.

4. This system uses a negative backpressure valve which should hold vacuum with engine "OFF."

5. When engine is started, exhaust backpressure should cause vacuum to bleed off and valve should fully close.

Diagnostic Aids
Before replacing PCM, use an ohmmeter and check the resistance of each PCM controlled relay and solenoid coil.

Refer to "PCM Wiring Diagram" for coil terminal ID of solenoid(s) and relay(s) to be checked.

Replace any solenoid where resistance measures less than 20 ohms.