Circuit/System Testing
- Ignition OFF, disconnect the fuel pump relay.
- Ignition ON, verify that a test lamp illuminates between the ground circuit terminal and B+.
- If the test lamp does not illuminate, test the ground circuit for a short to voltage or an open/high resistance.
- Verify that a test lamp does not illuminate between the ground circuit terminal and the control circuit terminal.
- If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- Remove the test lamp.
- Command the fuel pump relay ON with a scan tool. Verify the scan tool fuel pump relay Ckt. Short Grnd Test Status parameter is OK.
- If not the specified value, test the fuel pump relay control circuit for a short to ground. If the circuit tests normal, replace the ECM.
- Install a 3A fused jumper wire between the fuel pump relay control circuit terminal and the ground circuit terminal. Command the fuel pump ON with a scan tool. Verify the scan tool fuel pump relay Ckt. Short Grnd Test Status parameter is Fault.
- If not the specified value, test the fuel pump relay control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
- If all circuits test normal, test or replace the fuel pump relay.