Trouble code solution P025A: decoding, causes, resetting, meaning

Contents

Technical description and explained code P025A
Symptoms of vehicle malfunctions
Factors that can cause this error code
How to fix or reset OBD-2 code P025A
Diagnose and repair of problems
On which vehicles does this problem occur most frequently
Video

Fault code P025A is called “Fuel Pump Module Control Circuit/Open” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.

Technical description and explained code P025A

OBD-2 code P025A is most commonly defined as “Fuel Pump Module Control Circuit Open”. It is set when the PCM does not receive the required information from the fuel pump control module.

In most cases, the code is set immediately after the fault occurs and the signal lamp lights up. But sometimes the code is set only after the fault has been present for a few seconds.

On older gasoline engines, the fuel system is designed so that fuel flows to the injectors at a constant rate and pressure. In these systems, power is supplied to the fuel pump through a relay that supplies a voltage close to the battery voltage.

Modern vehicles use non-return systems that do not return excess fuel to the tank. Instead, the volume and pressure of fuel delivered to the injectors is controlled by changing the speed of the fuel pump, which is accomplished by changing the voltage in the control circuit.

The downside of these systems, however, is the greatly increased complexity of fuel pump control. Which includes control modules and various sensors. Such as accelerator pedal position, throttle position. Inputs from MAP / MAF, coolant, intake air temperature, fuel pressure and several others. Which are interconnected via the Controller Area Network (CAN) bus system.

The PCM uses all these inputs to calculate the appropriate fuel pressure. To achieve the correct balance, the PCM adjusts the speed of the fuel pump several times per second by changing the input voltage. There are various ways to do this, but the most common method is to change the resistance to increase or decrease the voltage.

The PCM activates error code P025A when it monitors one or more conditions outside a certain electrical range in the fuel pump control module or its circuit. This may be caused by a mechanical or electrical problem.

An error related to an open circuit in the fuel pump module control circuit is set when the PCM monitors a general fault or an open circuit. The problem may be in the fuel pump module itself or in its circuit.

Symptoms of vehicle malfunctions

The main signal that an error P025A has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.

It can also be warning signs such as:

The “Check engine” control lamp on the control panel will light up (the code will be stored as a fault).
Other related fault codes may also be present.
The engine may fail to start or may start and then stall.
Floating revolutions, and attempts to stall while idling.
Insufficient fuel supply due to improper fuel pump operation.
Reduced power output of the engine.
Increased fuel consumption.
Presence of fuel odor.
Engine stalls when reaching operating temperature.
There may be no symptoms other than a stored fault code.

A fault in the fuel pump module circuit may cause problems with the engine starting, so error P025A is considered serious. If it is ignored, components may fail completely.

Factors that can cause this error code

The error code P025A can mean that one or more of the following problems have occurred:

Problems with the fuel pump module.
Faulty fuel pump.
Fuel pump relay is faulty, and no voltage is supplied to the fuel pump.
Damaged wiring harness leads to breakage of fuel pump power supply circuit.
Loose or damaged connectors.
The feedback circuit is open.
A small impact may have tripped the inertia switch which opens the fuel pump circuit.
Fuel pump fuse blown due to short to ground.
Faulty CAN bus line.
Sometimes the cause is a faulty PCM module.

How to fix or reset OBD-2 code P025A

Some suggested steps for troubleshooting and fix the error code P025A:

Read all stored data and error codes with an OBD-II scan tool. To find out when and under what circumstances error P025A appeared.
Clear the error codes from the computer memory and test-drive the vehicle to find out if the malfunction appears again.
Test the fuel pump module.
Check that the fuel pump is working properly.
Test the fuel pump relay.
Visually inspect electrical wires and connections for looseness and damage.
Check the inertia switch, turn it on if necessary.
Replace fuse if necessary.
Clear the error code from the computer memory again, test drive the vehicle to see if the problem is resolved.

Diagnose and repair of problems

To diagnose the fuel pump circuits and clear the P025A trouble code, you will need a wiring diagram for your vehicle. After that you can proceed with further actions.

If the car starts and moves, there are no drivability complaints, most likely there is a break in the feedback circuit between the PCM and the fuel pump supply voltage circuit. Repair if necessary.

When the car won’t start or starts and shuts down because of low fuel pressure, check the fuel pump fuse. If it is blown, check the fuel pump supply circuit for a ground fault.

Remove the fuel pump relay (FP), and then check the resistance between the fuel pump connector voltage circuit and the ground. If there is a small resistance indicating a ground fault, disconnect the fuel pump and check it again.

If the fuel pump shows high or infinite resistance after disconnecting it, replace the shorted fuel pump. If the resistance is low after disconnecting the fuel pump, repair the short in the FP supply circuit.

After checking the electrical circuits, there will likely be several scenarios. Either the P025A error will go away because the wiring problem has been corrected. Or the problem is a faulty relay, module, or fuel pump itself.