Circuit/System Testing

Engine running, accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.6 and 15.0 V.
- If not within the specified range, refer to Charging System Test .
Ignition OFF, disconnect the harness connectors at the ECM.
Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 Ω between the ground circuit terminals listed below and ground.
- Terminal 1 X2 (LNF)
- Terminal 2 X2 (LNF)
- Terminal 4 X2 (LNF)
- Terminal 73 X2 (LE8/LE9)
- If greater than the specified range, test the ground circuit for an open/high resistance.
Verify that a test lamp illuminates between the B+ circuit terminals listed below and ground.
- Terminal 56 X2 (LNF)
- Terminal 20 X1 (LE8/LE9)
- If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
If all circuits test normal, replace the ECM.