Open circuit, corroded or loose terminals or damaged wiring in the fuel pump feed or control circuit; Faulty fuel pump relay or its socket, or a blown fuse; Failed fuel pump with an open internal winding; Poor earth connection on the pump circuit; Faulty fuel pump control module or driver, on vehicles that have one; Fault inside the engine control unit driver circuit.

P023F

Fuel Pump Secondary Circuit/Open.

Generic
Powertrain
Generic code
High severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
2: AreaFuel and air metering (injector circuit)
3F: FaultThe specific fault in that area

What it means

P023F is the generic code for an open circuit in the fuel pump secondary circuit. The secondary circuit is the pump's power feed or driver side, depending on the vehicle's design. The control unit saw no current flow, or a voltage that matched an open circuit, when it commanded or monitored the pump. The exact circuit layout and which module monitors it vary by model and engine, so check the manufacturer wiring diagram.

Symptoms

Engine cranks but fails to start, or starts and then stalls
Loss of power or hesitation under load
Intermittent cutting out, especially over bumps or when warm
Engine management warning light on
Fuel pump not audible when the ignition is switched on

Possible causes

Open circuit, corroded or loose terminals or damaged wiring in the fuel pump feed or control circuitlikely
Faulty fuel pump relay or its socket, or a blown fuselikely
Failed fuel pump with an open internal windingpossible
Poor earth connection on the pump circuitpossible
Faulty fuel pump control module or driver, on vehicles that have onepossible
Fault inside the engine control unit driver circuitrare

How to diagnose

Read all stored codes and freeze frame data to see engine speed, load and battery voltage when the fault set, and note any related fuel pump or fuel pressure codes
Check the relevant fuse and relay, and inspect the relay socket for heat damage or corrosion
Inspect the pump connector, wiring and any in-line connectors for damage, water ingress or pushed-out pins, particularly near the fuel tank and under the vehicle
Listen for the pump priming with the ignition on, and use a scan tool to command the pump if the vehicle supports it
With the circuit supplied, check for battery voltage and a good earth at the pump connector using a multimeter, following the wiring diagram for your model
Test continuity of the feed and control wires between the pump connector and the relay or control module, and wiggle the harness to reveal intermittent faults
Measure fuel pressure against the manufacturer's specification to confirm the pump delivers when powered
Check the pump control module connector and its power and earth supplies before condemning the module

How to fix

Repair or replace damaged wiring and clean or renew corroded connectors and terminals
Replace a faulty fuel pump relay or blown fuse, and trace the cause if the fuse blows again
Restore a poor earth connection by cleaning and refastening the earth point
Replace the fuel pump if its winding is open or it fails the voltage and pressure tests
Replace or reprogram the fuel pump control module only after wiring, supply and earth are proven good, and only if the manufacturer procedure requires it

Can I keep driving?

High severity

Avoid driving if the car is stalling, cutting out or struggling to start, as sudden loss of fuel delivery can leave you without power in traffic. Have it repaired promptly rather than relying on it.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.