Engine Control Module
- Ignition OFF, disconnect the harness connectors at the K20 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 73 X2 (LF1)
- Terminal 73 X3 (LF1)
- Terminal 1 X2 (LAU)
- Terminal 2 X2 (LAU)
- Terminal 4 X2 (LAU)
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Connect a 15 A fused jumper wire between B+ and the ECM PWR/TRN relay switch control terminal 87. Ignition ON, verify that a test lamp illuminates between the IGN/B+ circuit terminals listed below and ground:
- Terminal 52 X1 (LF1)
- Terminal 70 X1 (LF1)
- Terminal 73 X1 (LF1)
- Terminal 3 X2 (LAU)
- Terminal 5 X2 (LAU)
- Terminal 6 X2 (LAU)
- Terminal 41 X2 (LAU)
- Terminal 56 X2 (LAU)
- Terminal 54 X2 (LAU)
- If the test lamp does not illuminate, test the IGN/B+ circuit for a short to ground or an open/high resistance.
- If all circuits test normal, replace the K20 ECM.