Code 32 - EGR System Failure

Code 32 indicates that the EGR diagnostic switch was closed during start-up or that the switch was not detected closed under the following conditions: coolant temperature greater than 194° (94°C), EGR duty cycle controlled by ECM, greater than 50%, TPS less than wide open throttle, but above 5%, and all listed conditions must be met for about 4 minutes.

If switch is detected closed during start-up, the "SERVICE ENGINE SOON" light will come on within 40 seconds and stay on until the switch is detected open or until the engine is turned off. However, if the switch is detected open when the above conditions are met, the "SERVICE ENGINE SOON" light will only remain on while all conditions are met.

The EGR vacuum control uses an ECM controlled pulse width modulated EGR solenoid. The valve is normally closed and vacuum source is a ported signal. The ECM will turn EGR on and off (duty cycle) by grounding circuit No. 435. The duty cycle is calculated by the ECM based on information from coolant, MAP and TPS sensors and engine RPM. Duty cycle should be zero (no EGR) when in Park or Neutral, if TPS input is below a specified value or TPS indicates wide open throttle.

With ignition on, and engine stopped, the EGR solenoid is de-energized. The solenoid, however, should be energized if the diagnostic terminal is grounded under the same conditions.

1. This step checks circuit No. 935 for short to ground during start-up or temperature switch stuck closed.
2. This step checks to see if fault is switch or if it is faulty wiring to ECM.
3. This step checks for an open in circuit No. 935.
4. This step determines whether control solenoid, wiring or ECM is faulty.

Fig 1: Flow Chart, Code 32: EGR System Failure

Fig 2: Flow Chart, Code 32: EGR System Failure