Fuel and air

P025C — Fuel Pump Module Control Circuit Low

Severity: medium Drive with care, to a shop

What P025C means

The engine control module commands the fuel pump module through a control circuit and monitors the signal level. P025C sets when that voltage is lower than expected, for example due to an open circuit, a short to ground, a poor connection or a failing module. Fuel delivery may become unstable or stop altogether.

Symptoms

  • Check Engine light is on
  • Hard starting or no start
  • Hesitation or loss of power under acceleration
  • Engine stalls while driving or idling
  • Rough idle
  • Poor fuel economy

Possible causes

  1. Failed fuel pump module or its driver electronics
  2. Open, chafed or corroded wire in the control circuit
  3. Dirty or loose connector terminals
  4. Faulty fuel pump relay or blown fuse
  5. Poor ground connection
  6. Rarely, a faulty engine control module

How to diagnose

  1. Scan for codes and freeze frame data, and note any other fuel or power supply codes
  2. Check the fuel pump fuse and relay, swapping in a known good relay if in doubt
  3. Inspect the pump module connector and harness for corrosion, moisture or chafing
  4. Test the pump and module grounds with a voltage drop test
  5. Check battery voltage supply and the PCM control signal at the connector with a meter or scope
  6. Test the control wire for opens and shorts to ground
  7. Check fuel pressure and command the pump with a scan tool active test
  8. If wiring and power are good, suspect the pump module first, then the PCM

Common fixes

  • Repair or replace damaged wiring and connectors
  • Replace the fuel pump relay or fuse
  • Clean and tighten ground connections
  • Replace the fuel pump module
  • Repair or replace the PCM (last resort)

Questions and answers

What does P025C mean?

The PCM found low voltage in the fuel pump module control circuit. The cause may be wiring, power supply, ground or the module itself.

Can I drive with P025C?

Only a short distance to a shop. The engine may lose power or stall and then refuse to restart.

What should I check first?

Start with the fuel pump fuse and relay, then the module connector and ground. These are the simplest and most common causes and cost little to check.

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.