Powertrain Control Module PCM

DTC 32 Chart (NBP):

DTC 32 Circuit (NBP):

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.

DTC 32 Will Set When: 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 O2S 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.

The PCM will check EGR operation when:

^ Throttle position between 10% and 25% angle.

^ Steady throttle with no more than 2% change in throttle.

^ Above 32 mph "Closed Loop" operation.

^ Max short term fuel trim less than 6 counts for 3.2 seconds.

^ Desired EGR command greater than 93%.

^ MAP above 47.5 kPa or less than 15 kPa.

Action Taken (PCM will default to): The Malfunction Indicator Lamp (MIL) will illuminate.

DTC 32 Will Clear When: Conditions for fault are no longer present and Tech 1 "clear DTCs" function is used or 50 ignition switch keycycles have passed with no further faults or ignition switch is turned "OFF" and 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 causes 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 C Charts / ECM QDR Check Procedure. ECM QDR Check Procedure
Replace any solenoid where resistance measures less than 20 ohms.