Technical Description of OBD-II Trouble Code
Range/Performance Issue with Fuel Pump Module Control
What does that signify?
This generic powertrain diagnostic trouble code (DTC) is applicable to all OBD-II vehicles that have a fuel pump control module, including vehicles from Ford, Chevrolet, Dodge, Chrysler, Audi, VW, Mazda, etc.
In the past, vehicles required minimal fuel pressure. However, with the introduction of fuel injection and other systems, modern vehicles now require higher fuel pressures.
The Engine Control Module (ECM) relies on the Fuel Pump Module to regulate fuel pressures within the system and deliver fuel to the engine. If there is a failure in this module, it will likely be evident as the car may not start. An internal combustion engine requires three main things to run: air, fuel, and spark. If any of these are missing, the engine will not operate.
The ECM triggers the P025B code and related codes when it detects one or more conditions outside the specified electrical range within the Fuel Pump Control Module or its circuit. This can be caused by either a mechanical or electrical problem. It is important to exercise caution when diagnosing or repairing this area due to the potential hazards involved.
The P025B Fuel Pump Module Control Range/Performance code is set when the ECM identifies an out-of-range condition within the Fuel Pump Module or its circuits. It is one of four related codes, which are P025A, P025B, P025C, and P025D.
What is the severity of this DTC?
The severity of this code depends on the symptoms experienced. If the car does not start, the situation is severe. However, if the vehicle is operating normally and fuel mileage is not affected despite the active code, the situation is not very severe. Nevertheless, neglecting any fault may result in additional time and costs.
An example of a fuel pump control module:
What are some of the symptoms of the code?
Symptoms of a P025B trouble code may include:
What are some of the common causes of the code?
Possible causes for this code may include:
What are some P025B troubleshooting steps?
It is recommended to check for technical service bulletins (TSBs) for your vehicle as accessing a known fix can save time and money during diagnosis.
Tools
Some of the tools you may need when diagnosing or repairing the fuel pump circuits and systems include:
Safety Tips
NOTE: ALWAYS verify and record the integrity of your battery and charging system before further troubleshooting.
Basic Step #1
If the car does not start, a simple backyard diagnosing approach is to give the fuel tank a hit with a rubber mallet while someone tries to start the vehicle. If the vehicle starts up, the diagnosis is complete, and the fuel pump itself needs to be replaced.
NOTE: When diagnosing or repairing anything involving the fuel system, ensure that there are no fuel leaks present. Working around fuel with metal tools is a hazardous situation. Be cautious!
Basic Step #2
Inspect the connectors and wires. Due to the location of most fuel pumps and circuits, they may be difficult to access. You may need to elevate the vehicle (using ramps, jacks, stands, hoist, etc.) to gain better access to the connectors. Typically, the pump’s harnesses are exposed to extreme conditions as they are routed under the vehicle. Ensure that the connectors are securely fastened and undamaged.
NOTE: Sometimes these harnesses are routed along frame rails, rocker panels, and other locations where wire pinching is common.
Basic Tip #3
Test the fuel pump. Testing the Fuel Pump may not be an easy task. If the fuel pump’s connector is accessible, you could use a multimeter to perform a series of tests to verify the functionality of the fuel pump itself.
NOTE: Refer to your service manual for specific tests that can be conducted. There is no generic test, so ensure that you have the correct information before proceeding.
Basic Step #4
Check for the presence of a fuse or relay. A blown fuse could potentially cause an open condition in the circuit (P025A).
Basic Step #5
To verify the integrity of the wires within the circuit, you may be able to disconnect the circuit at both the fuel pump and the ECM. If this is possible, you could perform a series of tests to determine:
1. if there is a fault within the wires and/or
2. what type of fault is present.
