Exhaust Gas Recirculation: Testing and Inspection

Chart C-7 - Exhaust Gas Recirculation (EGR) Valve Check:

Wiring Diagram for Chart C-7 - Exhaust Gas Recirculation (EGR) Valve Check:

CHART C-7 - EXHAUST GAS RECIRCULATION (EGR) VALVE CHECK

Circuit Description:

The ECM energizes the solenoid to turn the EGR on, and monitors control vacuum to the EGR using the EGR diagnostic switch. Any EGR problem caused by the control solenoid, vacuum switch, wiring, or a vacuum leak should be detected by the ECM, and Code E032 will be set. Chart C-7 checks for two problems; plugged EGR passages, or a sticking EGR valve.

Code E032 will set if:

a. There is no vacuum at EGR switch above idle, or there is vacuum at idle.

b. There is a vacuum leak between EGR solenoid and EGR valve.




Test Description:

The following numbered steps correspond with the step numbers on diagnostic charts.

1. Checks for a sticking EGR valve and verifies available vacuum of 15". If EGR valve is sticking, it must be replaced. A sticking EGR valve will most likely cause a rough idle condition.

2. Checks for plugged EGR passages. If passages are plugged, no change in idle will be noticed. Improper EGR operation may result in severe detonation on acceleration.