Circuit/System Testing
NOTE:
Do not replace the fuel pump control module based on a history DTC P2635. The DTC P2635 may be stored but that does not indicate a failure of the fuel pump control module. Refer to STRATEGY BASED DIAGNOSIS for further history DTC diagnostics.
- Verify that DTCs P018C, P018D, P0231, P0232, or P023F are not set.
- If the DTC is set, refer to DIAGNOSTIC TROUBLE CODE (DTC) LIST - VEHICLE .
- Perform the Fuel System Diagnosis to verify proper fuel pressure.
- If the fuel pressure is not normal, replace the G12 Fuel Pump.
- 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.
- If all circuits test normal, replace the K27 Fuel Pump Control Module.