Diagnostic Instructions
| • | 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. |
DTC Descriptor
DTC P2632: Fuel Pump Relay 2 Control CircuitDiagnostic Fault Information
Circuit | Short to Ground | High Resistance | Open | Short to Voltage |
|---|---|---|---|---|
Fuel Pump Relay Control | P2632³ | ¹ | P2632³ | P2632² |
Fuel Pump Relay Ground | -- | P2632 | P2632 | ³ |
Fuel Pump Relay Battery Voltage | ³ | ¹ | ³ | ² |
Fuel Pump Supply Voltage | ³ | ¹ | ³ | ² |
Fuel Pump Ground | -- | ¹ | ³ | ³ |
¹ Low current, fuel pump runs slow ² Pump operates continuously, then discharges battery ³ Pump inoperative | ||||
Circuit/System Description
The fuel pump is located on the left frame rail between the fuel tanks. The engine control module (ECM) provides ignition positive voltage to the coil side of the fuel pump relay. The ECM energizes the fuel pump relay, which applies power to the fuel transfer pump. Fuel is transferred from the rear fuel tank to the front fuel tank in order to ensure all of the usable fuel volume is available to the engine.
The control module monitors the voltage on the fuel pump relay control circuit. If the control module detects an incorrect voltage on the fuel pump relay control circuit, a fuel pump relay control DTC sets.
Conditions for Running the DTC
Ignition is ON.
Conditions for Setting the DTC
| • | The ECM detects an incorrect voltage on the control circuit of the fuel pump relay. |
| • | The above condition exists for 1 second. |
Action Taken When the DTC Sets
DTC P2632 is Type C DTC.
Conditions for Clearing the DTC
DTC P2632 is Type C DTC.
Reference Information
Schematic Reference
Electrical Information Reference
Scan Tool Reference
Special Tools Required
J 43244 Relay Puller Pliers
Circuit/System Verification
- Turn ON the ignition, with the engine OFF.
- The fuel pump relay should click when the fuel pump is commanded ON and OFF with a scan tool.
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
- Turn OFF the ignition.
- Remove the fuel pump relay and turn ON the ignition, with the engine OFF.
- Connect a test lamp between the control circuit of the fuel pump relay and ground.
- Command the fuel pump ON and OFF with a scan tool. The test lamp should turn ON and OFF with each command.
- Connect a test lamp between the control circuit of the fuel pump relay and the ground circuit of the relay.
- Command the fuel pump ON and OFF with a scan tool. The test lamp should turn ON and OFF with each command.
| ⇒ | If the test lamp remains illuminated, test the fuel pump relay control circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
| ⇒ | If the test lamp does not turn ON and OFF with each command, test the fuel pump relay control circuit for a short to ground or an open. If the circuits test normal, replace the ECM. |
| ⇒ | If the test lamp does not turn ON and OFF with each command, test the fuel pump relay ground circuit for an open or high resistance. |
| ⇒ | If the test lamp turns ON and OFF with each command, replace the fuel pump relay. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM replacement, programing, and setup
