Circuit/System Testing
- Ignition OFF, the fuel pump should not be running.
- If the fuel pump runs continuously, test for a short to voltage. If the circuit tests normal, replace the fuel pump relay.
- Ignition OFF, remove the fuel pump relay from the electrical center with the J 43244
.
- Test for less than 5 ohms between the ground circuit terminal 85 and ground.
- If greater than the specified range, repair the ground circuit for an open/high resistance.
- Ignition ON, verify a test lamp illuminates between the relay switch B+ circuit terminal 30 and ground.
- If the test lamp does not illuminate, repair the B+ circuit for a short to ground or an open/high resistance. Replace the fuse if necessary.
- Connect a 15A fused jumper wire between the relay switch B+ circuit terminal 30 and the relay switch supply circuit terminal 87. The fuel pump should turn ON.
- If the fuel pump does not turn ON, test for the following conditions:
- An open/high resistance in the relay switch supply circuit
- An open/high resistance in the ground circuit
- If the above circuits test normal, replace the fuel pump.
- Ignition OFF, connect a test lamp between the relay coil control circuit terminal 86 and ground.
- Ignition ON, command the fuel pump relay ON and OFF with a scan tool. The test lamp should turn ON and OFF with each command.
- If the test lamp is always ON, test the relay coil control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- If the test lamp is always OFF, test the relay coil control circuit for a short to ground or an open/high resistance. If circuit tests normal, replace the ECM.
- If all circuits test normal, test or replace the fuel pump relay.