DTC 32

Code 32 - EGR System Failure:

Wiring Diagram For Code 32 - EGR System Failure:

CODE 32 - EXHAUST GAS RECIRCULATION SYSTEM FAILURE

Circuit Description:

The exhaust gas recirculation (EGR) valve is controlled by an ECM operated solenoid. The solenoid is normally closed and the vacuum source is a ported signal. The ECM will turn the EGR "ON" and "OFF" (Duty Cycle) by grounding CKT 435. The duty cycle is calculated by the ECM based on information from the coolant and MAP sensor and engine RPM. The duty cycle should be 0% (no EGR) when in Park or Neutral, TPS input below a specified value, or TPS indicating WOT.


Test Description: Step numbers refer to step numbers on diagnostic chart.

1. Code 32 means that the EGR vacuum switch was closed during start-up, or that the switch was not detected closed under the following conditions.

^ Coolant temperature greater than 85~C (185~F).
^ EGR duty cycle commanded by the ECM is greater than 70%.
^ TPS less than half throttle, but not at idle.
^ All conditions above must be met for 5 seconds.

If the switch is detected closed during start-up, or, if the switch is detected open when the above conditions are met, the "Service Engine Soon" light will remain "ON" unless the switch changes state.

2. If the first step caused Code 32 to set, then the ECM has recognized a closed vacuum switch on start-up. This test will determine whether the EGR control valve is the cause or, if the wiring or the ECM is the cause.


3. With the ignition "ON", the solenoid should not be energized and vacuum should not pass to the EGR valve.

4. The EGR solenoid and valve are OK and the following check will check the vacuum switch portion of the system.

5. The switch should close at about 2" of vacuum. With vacuum applied, the switch should close and resistance go to near zero ohms and the vacuum should hold.

Diagnostic Aids:

With the ignition "ON", engine stopped, the EGR solenoid is de-energized unless the diagnostic terminal is grounded.