• | 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 |
---|---|---|---|---|
Relay Switch Ignition 1 Voltage | * | ** | -- | -- |
Relay Switch Supply | * | ** | *** | -- |
Relay Coil Control | ** | ** | *** | -- |
Relay Coil Ground | -- | ** | -- | -- |
Fuel Pump Ground | -- | ** | -- | -- |
* The fuel pump fuse opens and the engine cranks but does not run. ** The engine cranks but does not run. *** The fuel pump operates continuously and the battery will discharge. |
The engine control module (ECM) provides a ground to the coil side of the fuel pump relay. When the ignition switch is first turned ON, the ECM turns ON the fuel pump relay, which applies power to the fuel pump. The ECM enables the fuel pump relay as long as the engine is cranking or running, and crankshaft reference pulses are received. If no crankshaft reference pulses are received, the ECM turns OFF the fuel pump relay after about 3 seconds.
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. |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
J 43244 Relay Puller Pliers
⇒ | If the fuel pump runs continuously, test the relay switch supply circuit for a short to voltage. If the circuit tests normal, replace the fuel pump relay. |
⇒ | If greater than the specified range, repair the ground circuit for an open/high resistance. |
⇒ | If the test lamp does not illuminate, repair the relay switch B+ circuit for a short to ground or an open/high resistance. Replace the fuse, if necessary. |
⇒ | 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. |
⇒ | 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 the circuit tests normal, replace the ECM. |
⇒ | If not within the specified range, replace the relay. |
• | 30 and 86 |
• | 30 and 87 |
• | 30 and 85 |
• | 85 and 87 |
⇒ | If not the specified value, replace the relay. |
⇒ | If greater than the specified range, replace the relay. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.