P0231 – Fuel Pump Primary Circuit Low

Description

The ECM detects low voltage in the fuel pump primary circuit, reducing fuel pressure.

Want to confirm the real cause of this fault code?

A high-quality OBD2 scanner gives you live data, fuel trims, sensor readings and freeze-frame information — exactly what you need to verify the root cause of this code with confidence.

View Recommended Scanners

Symptoms

  • Hard starting
  • Engine stalls
  • Poor acceleration
  • No start

Causes

  • Weak battery voltage
  • Faulty fuel pump relay
  • Damaged wiring
  • Failing fuel pump

Diagnosis

  • Check battery voltage
  • Inspect wiring and connectors
  • Test fuel pump relay
  • Measure fuel pressure

Repair

  • Replace relay
  • Repair wiring
  • Replace fuel pump