Powertrain Controls - ECM/PCM

DTC 32 EGR (Port) Chart:

DTC 32 EGR (Port) Circuit:

CIRCUIT DESCRIPTION:
The Powertrain Control Module (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 operating 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 40%.
^ 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 scan tool "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. With the ignition "ON," engine stopped, the solenoid should not be energized and vacuum should not pass to the EGR valve. Energizing the solenoid will allow vacuum to pass to the valve.
2. Checks for plugged EGR passages. If passages are plugged, the engine may have severe detonation on acceleration.
3. The vehicle must be driven during this test in order to produce sufficient engine load to operate the EGR. Lightly accelerating (approximately 1/4 throttle) will produce a large and stable enough reading to determine if the PCM is commanding the system "ON."

DIAGNOSTIC AIDS:
Before replacing the PCM, use an ohmmeter and check the resistance of each PCM controlled relay and solenoid coil.
For coil terminal identification of solenoid(s) and relay(s) to be checked, refer to PCM wiring diagram in ENGINE CONTROL MODULE/DIAGRAMS/ECM/PCM WIRING DIAGRAMS.
Electrical Diagrams
Replace any solenoid where resistance measures less than 20 ohms.
The EVRV solenoid cannot be diagnosed by an electrical check, because of the solid state circuitry involved.