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 P0230: Fuel Pump Relay Control CircuitDiagnostic Fault Information
Circuit | Short to Ground | High Resistance | Open | Short to Voltage |
|---|---|---|---|---|
Fuel Pump Relay Control | P0230³ | ¹ | P0230³ | P0230² |
Fuel Pump Relay Ground | -- | P0230 | P0230 | 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
| • | The control module stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records. |
| • | The driver information center, if equipped, may display a message. |
Conditions for Clearing the DTC
| • | A current DTC Last Test Failed clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic. |
| • | Clear the DTC with a scan tool. |
Reference Information
Schematic Reference
Electrical Information Reference
Scan Tool Reference
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.
- Engine running, observe the DTC information with a scan tool. DTC P0230 should not set.
- 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 Records data.
Circuit/System Testing
- Turn OFF the ignition.
- Remove the fuel pump relay and turn ON the ignition, with the engine OFF.
- Probe the control circuit of the fuel pump relay with a test lamp that is connected to a good ground.
- Command the fuel pump ON and OFF with a scan tool.
- 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.
| ⇒ | If the test lamp remains illuminated, test the fuel pump relay control circuit for a short to voltage or a faulty 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 control module. |
| ⇒ | 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
