• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Battery Voltage - Relay Switch Side | ¹ | ² | -- | -- |
Fuel Pump Supply Voltage | ¹ | ² | ³ | -- |
Fuel Pump Relay Control | P0230 | P0230 | P0230 | -- |
Fuel Pump Relay Ground | P0230 | P0230 | P0230 | -- |
Fuel Pump Ground | -- | ² | -- | -- |
¹Open fuel pump fuse, cranks no start ²Cranks no start ³Fuel pump operates continuously, then discharged battery |
The engine control module (ECM) enables the fuel pump relay when the ignition switch is turned ON. The ECM will disable the fuel pump relay within 2 seconds unless the ECM detects ignition reference pulses. The ECM continues to enable the fuel pump relay as long as ignition reference pulses are detected. The ECM disables the fuel pump relay within 2 seconds if ignition reference pulses cease to be detected and the ignition remains ON.
The following conditions may cause the fuel pump fuse to open:
• | The fuse is faulty. |
• | There is an intermittent short to ground in the supply voltage circuit of the fuel pump. |
• | The fuel pump has an intermittent internal condition. |
Control Module References for scan tool information
J 43244 Relay Puller Pliers
With the ignition ON, engine OFF, command the fuel pump relay ON and OFF several times using the scan tool output control function. You should either hear or feel the relay click and the fuel pump should turn ON and OFF with each command.
⇒ | If the fuel pump operates continuously, test for a faulty relay or a short to voltage in the supply voltage circuit of the fuel pump. |
⇒ | If the test lamp does not turn ON and OFF, test for an open or a short to ground in the fuel pump relay control circuit, an intermittent or a poor connection at the engine ECM or a faulty ECM. |
⇒ | If the test lamp remains illuminated with each command, test for a short to voltage in the control circuit of the fuel pump relay, an intermittent or a poor connection at the ECM, or a faulty ECM. |
⇒ | If the test lamp does not turn ON and OFF, repair the open or the high resistance in the ground circuit of the fuel pump relay. |
⇒ | If the test lamp does turn ON and OFF, test for an intermittent and for a poor connection at the fuel pump relay, or a faulty fuel pump relay. |
⇒ | If the fuel pump fuse is open, test for a short to ground in the supply voltage circuit of the fuel pump, or a faulty fuel sender. |
⇒ | If the test lamp does not illuminate, repair the open in the battery positive voltage circuit. |
⇒ | If the fuel pump operates, test for an intermittent or poor connection at the fuel pump relay, or a faulty fuel pump relay. |
⇒ | If the fuel pump does not operate, test for an open or high resistance in the supply voltage circuit of the fuel pump, an open or high resistance in the ground circuit of the fuel pump, an intermittent or poor connection at the fuel sender cover, or a faulty fuel sender. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |