DTC 32

Fig. 047 - WIRING DIAGRAM for Code 32 EGR System Failure. VIN S:

CODE 32, EGR SYSTEM FAILURE

Code 32 means that the EGR diagnostic switch was closed during start-up or that the switch was not detected closed under the following conditions.
a. Coolant temperature greater than 80°C (176°F).
b. EGR duty cycle commanded by the ECM is greater than 55%.
c. TPS less than half throttle, but not at idle.
d. All conditions above must be met for about 5 minutes.
If the switch is detected closed during start-up, the "Check Engine" light will come "ON" and stay on unless the switch opens. If the switch is detected open when the above conditions are met, the "Check Engine" light will only remain "ON" until the switch is detected closed or the ignition is cycled off.
The EGR vacuum control uses an ECM controlled EGR valve. The valve 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 mass air flow 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 Wide Open Throttle (WOT).
With the ignition "ON", engine stopped, the EGR solenoid is de-energized unless the diagnostic terminal is grounded.

Fig. 046 - Chart - Code 32 EGR System Failure:

1. 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.
2. With the ignition on, the solenoid should not be energized and vacuum should not pass to the EGR valve.
3. To this point the EGR solenoid and valve are OK and the following check will check the diagnostic vacuum switch portion of the system.
4. The diagnostic switch should close at about 2" of vacuum. With vacuum applied, the switch should close and resistance go to near zero ohms. The switch should also hold vacuum or it is defective.