Fuel and air

P000F — Fuel System Over Pressure Relief Valve Activated

Severity: medium Drive with care, to a shop

What P000F means

P000F means fuel pressure, typically in a direct injection rail, rose above the allowed limit and the over pressure relief valve opened. Normally the PCM holds pressure in range using a pressure regulator or the high pressure pump's metering valve, and monitors it with a rail pressure sensor. When that control fails, the relief valve vents the excess and the PCM stores the code.

Symptoms

  • Check Engine light on
  • Hard or delayed starting
  • Rough idle or hesitation
  • Weak acceleration
  • Worse fuel economy
  • Occasional stalling

Possible causes

  1. Faulty fuel pressure regulator or pump metering valve
  2. Fuel pressure sensor giving wrong readings
  3. Restricted fuel return line or clogged fuel filter
  4. Failing high pressure fuel pump
  5. Damaged wiring or poor connector contact
  6. Faulty or stuck relief valve

How to diagnose

  1. Scan for all codes and freeze frame data, and note any other fuel system codes
  2. Inspect wiring and connectors at the pressure sensor, regulator and pump, checking power and ground
  3. Compare actual and commanded rail pressure on a scan tool at idle and under load
  4. Check the pressure sensor reading with the engine off and verify with a mechanical gauge
  5. Inspect the return line for kinks or blockage and check the fuel filter condition
  6. Test the regulator or metering valve and the PCM control signal
  7. Test the high pressure pump and relief valve following the manufacturer's procedure

Common fixes

  • Replace the pressure regulator or metering valve
  • Replace the fuel pressure sensor
  • Clear or replace the return line and fuel filter
  • Replace the high pressure pump or its relief valve
  • Repair wiring and connectors

Questions and answers

What does P000F mean?

Fuel pressure became too high and the over pressure relief valve opened. The PCM logged it and turned on the check engine light.

Can I drive with P000F?

Only a short distance to a shop. High pressure can damage fuel system parts, and the engine may stall.

What most often causes P000F?

Most often a bad pressure regulator or pump metering valve, followed by the pressure sensor, a restricted return line and wiring problems.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.