Fuel and air

P023F — Fuel Pump Secondary Circuit Open

Severity: medium Drive with care, to a shop

What P023F means

Code P023F means the engine control module found an open circuit or other electrical fault in the secondary control circuit of the fuel pump. The pump is normally switched through a relay or a dedicated pump driver module, and the ECM monitors voltage and current in that circuit. When the readings are out of range, it stores the code and turns on the check engine light.

Symptoms

  • Check engine light on
  • Hard starting or no start
  • Loss of power or hesitation under acceleration
  • Engine stalling while driving
  • No pump hum when the ignition is turned on, or unusual pump noise
  • Fuel pump running with the ignition off

Possible causes

  1. Faulty fuel pump relay
  2. Open, chafed, or corroded wiring or connector in the pump circuit
  3. Failed fuel pump or internal pump circuit
  4. Blown fuse or poor ground in the pump circuit
  5. Faulty fuel pump driver module
  6. Rarely, a faulty ECM

How to diagnose

  1. Scan all codes and freeze frame data and note any other fuel system codes
  2. Turn the ignition on and listen for the pump to prime for a few seconds
  3. Check the pump fuse and relay, and swap in a known good relay if possible
  4. Inspect the wiring harness and connectors from the relay to the pump and driver module for breaks, corrosion, and chafing
  5. Test for power and ground at the pump connector with a multimeter, following the factory wiring diagram
  6. Check the circuit wires for opens and shorts with the battery or connector disconnected
  7. Measure fuel rail pressure and compare it to specification
  8. If the circuit is good, test the pump and the driver module

Common fixes

  • Replace the fuel pump relay
  • Repair the wiring or replace the damaged connector
  • Replace the fuel pump
  • Replace or reprogram the fuel pump driver module or the ECM

P023F on different brands

Ford · manuals
On Ford, P023F:11 is documented as fuel pump secondary circuit low (short to ground); it identifies the monitor condition that was detected, not a confirmed failed part.

Questions and answers

Can I drive with code P023F?

It is best not to. A fault in the pump circuit can cut fuel delivery and stall the engine without warning. Only drive carefully to a shop if you have to.

What should I check first for P023F?

Start with the fuel pump fuse and relay, then inspect the wiring and connectors. These are the most common and cheapest causes.

Does P023F always mean a bad fuel pump?

No. The relay, wiring, or a connector is often at fault. Replace the pump only after confirming power, ground, and fuel pressure.

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.