Engine Control Module: Testing and Inspection
CHECK ECM POWER SUPPLY CIRCUITECM Power Supply:
1. With ignition "OFF," disconnect ECM harness connectors.
2. Turn ignition "ON" and check for battery voltage at terminals "33," "12" and "21."
3. Ensure that continuity exists between terminals "11" and "20" and ground.
4. If voltage is not present at terminals "33," "12" or "21," check the main relay, ignition switch, fuses, fusible links and related circuits. Repair and/or replace defective components as necessary.
5. Repair or replace ground cable if continuity does not exist between terminals "11" and "20" and ground.
6. When testing and repair is completed, switch ignition "OFF" before reconnecting wiring harness to ECM.
ECM Connector Identification:
ECM Terminal Identification:
ECM CONNECTOR PIN IDENTIFICATION