What is the DTC code for a fuel pump?
There is no single universal DTC code for a fuel pump; codes vary by fault and by vehicle. The most commonly encountered fault codes relate to the pump circuit or the fuel rail pressure system, such as P0230, P0231, P0232, P0087, P0088, P0191, and P0193.
What these codes mean for the fuel system
Diagnostic Trouble Codes (DTCs) are saved by a vehicle’s engine control unit (ECU) when it detects an issue with the fuel delivery system. In practice, “fuel pump” related codes can indicate a problem with the pump’s electrical circuit, the pump relay, wiring, or with the fuel pressure entering or leaving the rail. Manufacturer-specific interpretations can vary, so a code may have slightly different wording depending on the make and model.
Common DTCs related to the fuel pump
Below are the most frequently seen fuel-pump related DTCs in OBD-II equipped vehicles. The exact wording and applicability can differ by manufacturer and model-year.
- P0230 — Fuel Pump Primary Circuit Malfunction
- P0231 — Fuel Pump Secondary Circuit Low
- P0232 — Fuel Pump Secondary Circuit High
- P0087 — Fuel Rail Pressure Too Low
- P0088 — Fuel Rail Pressure Too High
- P0191 — Fuel Rail Pressure Sensor Circuit Range/Performance
- P0193 — Fuel Rail Pressure Sensor Circuit High Input
Notes on these codes: P0230/P0231/P0232 point to electric or control circuitry around the pump or its power supply. P0087 and P0088 relate to abnormal fuel pressure in the rail, while P0191 and P0193 pertain to the fuel rail pressure sensor’s readings or wiring. A single code may trigger additional codes as the ECU stores related fault information.
Manufacturer variations
Some automakers use slightly different code wording or have additional, vehicle-specific codes for the fuel pump and related components. Always check the vehicle’s service manual or a manufacturer-specific diagnostic database for exact definitions and test procedures.
How to diagnose fuel pump-related DTCs
Before performing diagnostics, ensure you follow proper safety procedures for working with the fuel system, including relieving system pressure and disconnecting the battery when needed. The process below outlines a practical approach that applies to most modern vehicles.
- Connect an OBD-II scanner and retrieve all current and pending DTCs, along with freeze-frame data and any live sensor readings.
- Inspect basic electrical power to the pump: verify battery voltage at the fuel pump relay/fusible link, check fuses, and test the pump relay with a known-good relay if possible.
- Test the fuel pressure with an appropriate gauge. Compare readings to the manufacturer’s specifications across key engine operating conditions (e.g., idle, at wide-open throttle, and under load).
- Inspect the fuel pump wiring harness and ground connections for corrosion, damage, or loose connections. Pay attention to signs of wiring chafing or short to ground.
- Check the fuel rail pressure sensor and its circuit (wiring, connector, and sensor itself) for proper operation and clean readings. Look for ducting or leaks that could affect readings.
- If electrical and pressure checks are normal but the DTC persists, consider a suspected failing fuel pump or a control module issue. In some vehicles, the pump may have intermittent operation or internal faults not detected by simple tests.
After performing these steps, document all measurements, compare them to the service manual, and follow the recommended testing sequence for your specific vehicle. If in doubt, consult a qualified technician or the manufacturer’s technical resources.
Summary
Fuel pump DTCs are codes that indicate problems in the pump’s electrical circuits, its relay, or the fuel rail pressure system. The most common codes are P0230, P0231, P0232, P0087, P0088, P0191, and P0193, but exact meanings can vary by manufacturer. A systematic diagnostic approach—combining code interpretation, electrical checks, and fuel pressure testing—will help identify whether the issue lies with the pump, the wiring, or the sensors.
In the end, accurate diagnosis hinges on using the vehicle’s service information, a reliable scan tool, and careful testing of both electrical and mechanical components within the fuel delivery system.
