DTC 32

Code 32 EGR System:

Wiring Schematic For Code 32:

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

The ECM monitors EGR effectiveness by de-energizing the EGR control solenoid thereby shutting off vacuum to the EGR valve diaphragm. With the EGR valve closed, fuel integrator counts will be greater than they were during normal EGR operation. If the change is not within the calibrated window, a Code 32 will be set.

The ECM will check EGR operation when:

^ Vehicle speed is above 50 mph.
^ Engine vacuum is between 40 and 51 kPa.
^ No change in throttle position while test is being run.

TEST DESCRIPTION
Numbers below refer to circled numbers 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. Grounding the diagnostic terminal will energize the solenoid and allow vacuum to pass to valve.
2. Checks for plugged EGR passages. If passages are plugged, the engine may have severe detonation on acceleration.
3. The EGR solenoid will not be energized in Park or Neutral. This test will determine if the Park/Neutral switch input is being received by the ECM.

DIAGNOSTIC AIDS
Before replacing ECM, use an ohmmeter and check the resistance of each ECM controlled relay and solenoid coil. Refer To ECM QDR check procedure. See ECM wiring diagram for coil terminal identification of solenoid(s) and relay(s) to be checked. Replace any solenoid where resistance measures less than 20 ohms.