What causes fault code P023F?

• Most likely: Blown fuel pump fuse or faulty relay • Likely: Open circuit or loose connector in the wiring harness to the pump or FPDM • Possible: Faulty fuel pump B (internal open winding) • Rare: Defective Engine Control Module (ECM) or Fuel Pump Driver Module (FPDM)

Powertrain (Engine & Gearbox)Standard EOBD

P023F - Fuel Pump B Control Circuit Open

Q: What are the symptoms of fault code P023F?

• Check Engine Light (MIL) illuminated • Engine may crank but not start, or stall shortly after starting • Reduced engine performance (Limp home mode) • Rough idle or hesitation during acceleration • Emission test failure

Q: How do you fix fault code P023F?

STEP 1: Check fuel pump fuses and the fuel pump relay for proper operation. STEP 2: Perform a visual inspection of the connectors at fuel pump B and the Fuel Pump Driver Module (FPDM) for corrosion or backed-out pins. STEP 3: Measure the supply voltage to the pump. It should typically show battery voltage (approx 12.6V) during the prime cycle. Check ground integrity (resistance should be < 0.5 Ohms to chassis). STEP 4: Test the fuel pump's internal motor resistance. An 'OL' or infinite reading indicates an internal open circuit. Replace pump if necessary. STEP 5: Use an oscilloscope to verify the PWM signal from the ECM/FPDM if the wiring and pump motor are confirmed functional.

Last updated:1 February 2026

Related:Fuel Pump, Fuel Pump Driver Module (FPDM), Engine Control Module (ECM), Fuel Pump Relay, Wiring Harness

System

Powertrain (Engine & Gearbox)

Related Fault Codes

P0200

Injector Circuit Malfunction

P0201

Cylinder 1 Injector Circuit Open

P0202

Injector Circuit - Cylinder 2 - Malfunction

P0203

Injector Circuit - Cylinder 3

Technical Description

Diagnostic Trouble Code (DTC) P023F is stored when the Engine Control Module (ECM/PCM) detects an open circuit within the control line of fuel pump 'B'. The ECM typically monitors the integrity of the fuel pump driver circuit by checking for voltage drop or feedback signals. If the circuit is broken (infinite resistance), the controller cannot actuate the pump. This is common in vehicles equipped with auxiliary fuel pumps or high-performance delivery systems using a dedicated Fuel Pump Driver Module (FPDM).

Possible Causes

Blown fuel pump fuse or faulty relay

Open circuit or loose connector in the wiring harness to the pump or FPDM

Faulty fuel pump B (internal open winding)

Defective Engine Control Module (ECM) or Fuel Pump Driver Module (FPDM)

Symptoms

Check Engine Light (MIL) illuminated

Engine may crank but not start, or stall shortly after starting

Reduced engine performance (Limp home mode)

Rough idle or hesitation during acceleration

Emission test failure

Do you also have
other fault codes?

See how P023F connects with your other fault codes. Our advanced analysis tool identifies causal relationships and root causes directly.

Analyze multiple codes

P023F - Fuel Pump B Control Circuit Open

Related Fault Codes

Technical Description

Possible Causes

Symptoms

Recommended Solution

Workflow

Mechanic's Tip

Do you also have
other fault codes?

P023F - Fuel Pump B Control Circuit Open

Related Fault Codes

Technical Description

Possible Causes

Symptoms

Recommended Solution

Workflow

Mechanic's Tip

Do you also have other fault codes?

Do you also have
other fault codes?