Chart C-7 Exhaust Gas Recirculation (EGR) Check

CIRCUIT DESCRIPTION
The EGR valve is controlled by a normally closed solenoid (allows vacuum to pass when energized). The Engine Control Module (ECM) energizes the solenoid to turn the EGR on and monitors vacuum to the EGR with the EGR diagnostic switch. Code 32 will detect a fault solenoid vacuum switch or vacuum supply. Chart C-7 checks for plugged EGR passages, a sticking EGR valve or a stuck open solenoid

CHART TEST DESCRIPTION
1. With the ignition "ON" engine stopped the solenoid should not be energized and vacuum should not pass to the EGR valve.

2. Grounding the diagnostic terminal will energize the solenoid and allow vacuum to pass to valve.

3. Checks for lugged EGR passages. If passages are plugged, the engine may have severe detonation on acceleration.

4. The EGR solenoid will not be energized in Park or Neutral. This test will determine if the Park/Neutral switch input is being received by the ECM.