Code Definition: P1251 - Fuel Level Sensor B Range/Performance
The P1251 code is a generic trouble code that indicates a problem with the fuel level sensor range or performance in bank B. The fuel level sensor is responsible for measuring the fuel level in the tank and sending a signal to the engine control module (ECM) so that the ECM can calculate the appropriate fuel injection volume. When the fuel level sensor range or performance is outside the acceptable limits, it can cause problems with the engine's performance and fuel efficiency.
Possible Causes:
- Faulty fuel level sensor
- Damaged or corroded wiring harness
- Loose or damaged electrical connectors
- Faulty fuel pump or fuel delivery system
- Incorrect fuel level sensor calibration
- Low fuel level
Symptoms:
- Illuminated check engine light
- Inaccurate fuel level readings
- Engine stalling or hesitation
- Difficulty starting the engine
- Decreased fuel efficiency
Diagnostic Procedure:
- Use a scan tool to retrieve the trouble code and view the freeze frame data to determine when the code was set and under what operating conditions.
- Check the fuel level sensor and its connections for any signs of damage or wear.
- Inspect the wiring harness and connectors for any signs of damage or corrosion.
- Test the fuel pump and fuel delivery system to ensure they are functioning properly.
- Check the fuel level in the tank and make sure it is above the minimum level required by the fuel level sensor.
- Calibrate the fuel level sensor if necessary.
- If the problem persists, consider replacing the fuel level sensor or the affected component.
- Clear the code and perform a road test to verify the repair.
Repair Information:
- Replace the faulty fuel level sensor.
- Repair or replace any damaged or corroded wiring harness or connectors.
- Replace the faulty fuel pump or fuel delivery system component.
- Reprogram the fuel level sensor calibration.
- Clear the code and perform a road test to verify the repair.