Code 32, EGR Vacuum Control
The EGR vacuum control circuit has an ECM controlled solenoid that pulses manifold vacuum to the EGR valve. The solenoid is always de-energized (EGR "OFF") in Park or Neutral and at idle. The circuit also includes vacuum diagnostic switch which is open with no vacuum applied to the EGR. The diagnostic switch signals the ECM when vacuum is being applied to the EGR valve. Code 32 will set if the EGR diagnostic vacuum switch senses vacuum at idle, or if it does not sense vacuum in gear with moderate to heavy engine load, but less than wide open throttle.
NOTE:
The following step numbers refer to the numbers in the accompanying flow chart(s).
- This test checks for presence of vacuum to EGR valve at idle (closed vacuum switch).
- Grounding the test terminal causes the ECM to energize the solenoid by grounding circuit 435. Test light should be "ON."
- Light "ON" indicates vacuum at EGR. Vacuum should not be present.
- Normal response is "SERVICE ENGINE SOON" light "OFF." This indicates vacuum switch is open.
- "SERVICE ENGINE SOON" light "ON" indicates circuit 932 shorted to ground, or contacts stuck closed in EGR vacuum diagnostic switch.