DTC 32

Code 32 - Exhaust Gas Recirculation (EGR) Vacuum Control:

Wiring Diagram for Exhaust Gas Recirculation (EGR) Vacuum Control:

CODE 32 - EXHAUST GAS RECIRCULATION (EGR) VACUUM CONTROL



Circuit Description:

The EGR Vacuum Control has an ECM controlled solenoid that pulses manifold vacuum to the EGR valve. The solenoid is always de-energized (EGR off) in "park" or "neutral" and at idle. Another part of the control is a vacuum diagnostic switch which is open with no vacuum applied. Its purpose is to signal the ECM when vacuum is actually being applied to the EGR valve.

Code 32 will be set if the EGR diagnostic vacuum switch senses vacuum at idle, or if it does not sense vacuum in gear with moderate to heavy engine load, but less than WOT. The EGR valve is energized based on the following inputs:

Engine running above idle, but less than WOT.

Code 33 or 34 not present

Engine coolant temperature 42.5~C (108~F) or above.

Transmission in gear.


Test Description: Numbers below refer to circled numbers on the diagnostic chart.

1. Checks for presence of vacuum to EGR valve at idle. This would be indicated by a closed vacuum switch.

2. Grounding the test terminal of the ALCL causes the ECM to energize the solenoid by grounding CKT 435. The test light should be on.

3. Light "ON" indicates vacuum at EGR. Vacuum should not be present.

4. A "SERVICE ENGINE SOON" light "OFF" at this point indicates the vacuum switch is open, as it should be.

5. A "SERVICE ENGINE SOON" light "ON" indicates CKT 932 or wire from terminal "C" to vacuum switch possibly shorted to ground, or contacts stuck closed in the EGR vacuum diagnostic switch. If the diagnostic switch requires replacement, it is serviced seperate from the EGR solenoid.