Circuit/System Testing
- Verify that DTCs P018C, P018D, P0231, P0232, or P023F are not set.
- Ignition OFF, disconnect the harness connector at the G12 fuel pump.
- Ignition OFF, test for less than 5.0 Ω between the G12 fuel pump low reference circuit terminal A and ground.
- If greater than the specified range, test the G12 fuel pump low reference circuit for a high resistance. If the circuit tests normal, replace the K27 fuel pump control module.
- Ignition OFF, install a test lamp between the control circuit terminal D and the low reference circuit terminal A.
- Ignition ON, command the Fuel Pump Relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K27 fuel pump control module.
- If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K27 fuel pump control module.
- Perform the Fuel System Diagnosis (w/o FPCM)
or Fuel System Diagnosis (FPCM)
to verify proper fuel pressure.
- If the fuel pressure is not normal, replace the G12 fuel pump
- If all circuits test normal, replace the K27 fuel pump control module.