Fuel and air

P025B — Fuel Pump Module Control Circuit Range/Performance

Severity: medium Drive with care, to a shop

What P025B means

P025B means the engine control module detected that the fuel pump module control circuit is operating outside its expected range. The PCM normally sends a control signal, often PWM, to the module, which adjusts pump output to match engine demand. When the signal, voltage or feedback does not match what the PCM commanded, it sets the code and turns on the check engine light.

Symptoms

  • Check engine light on
  • Hard starting or no-start
  • Hesitation and loss of power
  • Rough or unstable idle
  • Engine stalling
  • Poor fuel economy

Possible causes

  1. Faulty fuel pump control module (electronics)
  2. Damaged wiring or corroded connectors in the pump control circuit
  3. Worn or failing fuel pump
  4. Blown fuse or bad fuel pump relay
  5. Low voltage from a weak battery or poor ground
  6. PCM fault (rare)

How to diagnose

  1. Scan for all codes and review freeze frame data, looking for related fuel pressure or voltage codes.
  2. Check the fuel pump fuse and relay; swap in a known good relay if possible.
  3. Inspect the pump module and PCM connectors and harness for corrosion, moisture, heat damage or breaks.
  4. Test battery voltage and the ground connection of the pump module.
  5. Verify power and the control signal at the module with the key on, using a multimeter or scope.
  6. Measure fuel pressure with a gauge and compare it to factory specs.
  7. Check pump current draw; high draw suggests a worn or restricted pump.
  8. If wiring and power are good, suspect the control module or PCM.

Common fixes

  • Replace the blown fuse or faulty relay
  • Repair wiring and clean or replace connectors
  • Replace the fuel pump control module
  • Replace the fuel pump, often as an assembly in the tank
  • Replace or reprogram the PCM if confirmed faulty

Questions and answers

What does P025B mean?

It is a range or performance fault in the fuel pump module control circuit. The PCM sees that the pump signal or feedback does not match what it expects.

Can I drive with P025B?

Only for a short distance, such as to a shop. The pump may fail suddenly and stall the engine, so avoid long trips.

What should I check first for P025B?

Start with the fuse, relay, connector and wiring for the pump, plus battery voltage and grounds. These are the simplest and most common causes, so rule them out before replacing the module or pump.

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.