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
An electric fuel pump is used to prime the fuel system after changing the fuel filter or servicing the fuel system. The fuel pump is part of the diesel fuel conditioning module (DFCM) assembly. The fuel pump is powered by the fuel pump relay. The fuel pump relay is controlled by the engine control module (ECM). The ECM enables the fuel pump when the ignition is turn on and will continue to run for 2 minutes or until the engine starts. If the engine does not start due to low fuel pressure and the ignition is left in the on position, the pump will run for up to 2 minutes or until the ignition is turned off. The ECM will also turn off the fuel pump if incorrect voltage is detected on the control circuit. The ECM will need to be powered down with a key cycle during diagnosis or after repairs, before it will command the fuel pump on again.
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 P0230 is a Type C DTC.
Conditions for Clearing the MIL/DTC
DTC P0230 is a Type C DTC.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Special Tools
| • | CH-48027 Digital Pressure Gage |
| • | J 43244 Relay Puller Pliers |
Circuit/System Verification
- Install the CH-48027 to the fuel system service port on the right from side of the engine. Command the fuel pump on, using a scan tool and observe the fuel pressure gage. Fuel pressure should be a minimum of 69 kPa (10 psi) with the fuel pump running.
- 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 circuit tests 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, setup, and programming
