DTC 32

Code 32 - EGR System Failure (Under 8500 GVW):

Wiring Diagram For Code 32 - EGR System Failure (Under 8500 GVW):

CODE 32 - EGR SYSTEM FAILURE (UNDER 8500 GVW)

Circuit Description:

The ECM operates a solenoid to control the Exhaust Gas Recirculation (EGR) valve. This solenoid is normally closed. By providing a ground path, the ECM energizes the solenoid which then allows vacuum to pass to the EGR valve.

The ECM monitors EGR effectiveness by de-energizing the EGR control solenoid thereby shutting off vacuum to the EGR valve diaphragm, With the EGR valve closed, fuel integrator counts will be greater than they were during normal EGR operation. If the change is not within the calibrated window, a Code 32 will be set.

The ECM will check EGR operation when:

^ Vehicle speed is above 50 mph.
^ Engine vacuum is between 40 and 51 kPa.
^ No change in throttle position while test is being run.


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

1. Checks for solenoid stuck open.

2. Checks for solenoid always being energized.

3. Grounding test terminal should energize solenoid and vacuum should drop.

4. Negative back pressure valve should hold vacuum with engine "OFF".

5. When engine is started, exhaust back pressure should cause vacuum to bleed off and valve to fully close.


Diagnostic Aids:

^ Before replacing ECM, use an ohmmeter and check the resistance of each ECM controlled relay and solenoid coil. See ECM wiring diagram for coil term. I.D. of solenoid(s) and relay(s) to be checked. Replace any solenoid where resistance measures less than 20 ohms.