P023F OBD Error Code: Problem & Solutions

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Is your vehicle’s Check Engine Light illuminated? Are you experiencing sudden decrease in engine power and acceleration? Is there a drop in the fuel economy with increased level of emissions? All these indicate problem with the fuel delivery system and the Powertrain Control Module, thus flashing OBD Code P023F error.

The Engine Control Module (ECM) provides ignition positive voltage to the coil side of the fuel pump relay. When the ignition switch is first turned ON, the ECM energizes the fuel pump relay, which applies power to the fuel pump. The ECM enables the fuel pump relay as long as the engine is cranking or running, and crankshaft reference pulses are received. If no crankshaft reference pulses are received, the ECM de-energizes the fuel pump relay after 2 seconds. The ECM monitors the voltage on the fuel pump relay control circuit.

The PCM monitors this feedback circuit to ensure that there is proper voltage being sent to the fuel pump. As it activates the fuel pump relay, it expects to see battery voltage on the feedback circuit. If the PCM sees an open condition with the signal when the fuel pump isn't activated, P023F may set.

What causes the problem of Fuel Pump Secondary Circuit/Open?

• Blown Fuel Pump fuse
• Open Fuel Pump Monitor Circuit
• Faulty Fuel Pump Relay
• Damaged Engine Control Module (ECM)
• Powertrain Control Module (PCM) failure

1. Fuel Pump - Check for any fuel pump and component failure due to high pressure situations. Replace them immediately.
2. Diagnostic Tools - Use professional diagnostic tools to detect and diagnose the OBD error problem. Buy best tools and equipment from us.
3. Engine Control Module - OBD Error Code P023F can also be due to faulty ECMs. This may lead to engine stalling or not starting, and check engine lights being on. It’s better to get the faulty electricals replaced as soon as possible.
4. Powertrain Control Module - P023F error code also relates to problems with the powertrain which can store and flash wrong error code. Find all the Powertrain related parts with us.
5. Fuel Pump Reply - If the fuel pump relay is faulty, replace it immediately as it will hamper the fuel delivery system and thus the performance.
6. Fuel Pump Module Assemble - There might be some problem with the pump assembly that might result in complete replacement of the component. Buy new assembly unit form us and replace now!

The symptoms of code P023F can appear suddenly, and may be dramatic in some cases.

Common Symptoms

• Sudden loss of power and the engine entering ‘limp mode’
• Loss of acceleration, and the transmission may refuse to shift
• Engine shut off unexpectedly, with the loss of power steering and vacuum assistance for the brakes
• Visible smoke from under the hood
• Engine misfires and failed startups
• Fuel pump runs with key off Small amount of voltage present on FP (fuel pump) voltage supply circuit due to short

Common measures and solutions are as follows;

• Fuel tank replacement
• Fuel pump replacement
• Fuel filter replacement
• Fuel injectors replacement
• Fuel injector pump replacement
• Fuel pressure regulator replacement
• Fuel hose or Fuel line replacement
• Fuel pressure sensor replacement
• Repairing or replacing wiring associated with the fuel pressure sensor

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It is possible with a P023F for the fuel pump to be running continuously, even with the ignition off. If that's the case and you can hear the fuel pump running, you may be able to disregard some of the following checks. Turn the KOEO (key on engine off) and wait for a few seconds. This allows the PCM to complete its fuel pump pre-cycle. Now, using your scan tool (if you have one) observe the FP Voltage Feedback reading in the data stream. This reading indicates what kind of voltage the fuel pump is receiving.

If you don't have access to a scan tool, use a voltmeter to read the FP voltage at the fuel tank. If you're reading shows any voltage at all present to the fuel pump with KOEO (or if you can hear the pump running), remove the FP relay. If the voltage remains, or the fuel pump continues to run, then there is a short to voltage on the FP voltage supply circuit or on the feedback circuit. Repair as necessary. If the voltage disappears (or the pump quits running) with the FP relay removed then try replacing the relay with a spare one. Upon reinstalling the spare relay, if the voltage disappears, the relay was faulty due to a short. If, though, after replacing the relay voltage is still present, suspect that the PCM FP relay control circuit is shorted to ground.

Check for a short to ground on the PCM FP relay control (ground driver) circuit by removing the FP relay and ohm between a good ground and the PCM FP relay control. There should be no continuity to ground with KOEO (after the FP pre-cycle is completed). If there is continuity to ground the wire is shorted. Find the short to ground and repair as necessary. If you can find no physical short, It may be necessary to snip the FP relay control wire close to the PCM connector where it will be easy to repair and check for continuity to ground with KOEO coming OUT of the PCM. If there is no continuity the wire is shorted in the harness. But if continuity exists, the driver may be internally shorted to ground and the PCM may require replacement.

Common Mistakes When Diagnosing The P023F Code

Check all the components for leakages. Do not replace any perfectly working component without inspection for damages or faults. This part is a common cause of this issue, however is always best to know for sure that a part is faulty by testing it before replacing anything.