Code 32 - EGR System Failure
EGR vacuum is regulated by an ECM-controlled solenoid. The solenoid is normally closed. Vacuum source is a ported signal. The ECM turns the EGR on and off (duty cycle) by grounding and ungrounding circuit No. 901. The duty cycle is calculated by ECM based on coolant temperature, airflow and engine RPM. The duty cycle should be zero percent (no EGR) when vehicle is in Park or Neutral, TPS input less than a specified value, or TPS indicating Wide Open Throttle (WOT).
With ignition on and engine stopped, the EGR solenoid is de-energized unless the diagnostic terminal is grounded. Code 32 means the EGR vacuum diagnostic switch was closed during start-up, or that the switch was not detected closed under the following conditions:
- Coolant temperature greater than a specified amount.
- EGR duty cycle command is greater than 50 percent.
- TPS less than half throttle, but not at idle.
- Manifold vacuum greater than 7 in. Hg.
- All conditions above must be met for 8 seconds.
If the switch is detected closed during start-up, or if the switch is detected open when above conditions are met, the "SERVICE ENGINE SOON" light remains on unless the switch changes state.
- With ignition on, solenoid should not be energized and vacuum should not pass to the EGR valve.
- To this point, the EGR solenoid and valve are okay. The following checks diagnose the vacuum switch portion of the system.
- The diagnostic switch should close at about 2 in. Hg. With vacuum applied, the switch should close and resistance should go to near zero ohms.
Before Using This Chart, Check For Ported Vacuum To EGR Solenoid. Also Check Hoses For Leaks Or Restrictions, Should Be At Least 7" Hg Vacuum At 2000 RPM.