B1279 – Servo Motor Potentiometer Foot Circuit Short To Ground
The ODBII code B1279 indicates a malfunction in the servo motor potentiometer circuit for the foot pedal, specifically a short to ground condition, which means there is an unintended connection to the ground that affects the circuit’s normal operation.
The severity of ODBII code B1279 is moderate to high.
Common Causes For: B1278 Servo Motor Potentiometer Foot Circuit Short To Battery
- Damaged wiring or connectors
- Faulty servo motor potentiometer
- Short circuit in the foot circuit
- Corroded or loose electrical connections
- Malfunctioning brake pedal switch
- Issues with the vehicle’s control module
Common misdiagnosis for B1279 Servo Motor Potentiometer Foot Circuit Short To Ground
- Faulty servo motor
- Damaged wiring or connectors
- Malfunctioning brake pedal switch
- Defective body control module (BCM)
- Issues with the accelerator pedal position sensor
- Shorted or damaged potentiometer
- Problems with the electronic throttle control system
Common Troubleshooting Steps
The OBD-II code B1279 indicates a problem with the servo motor potentiometer foot circuit, specifically a short to ground. This code is often associated with issues in the throttle control system, particularly in vehicles with electronic throttle control (ETC). Here are some common troubleshooting steps to diagnose and resolve this issue:
- Visual Inspection: **Wiring and Connectors: Check the wiring harness and connectors related to the servo motor potentiometer for any signs of damage, fraying, or corrosion. Look for loose connections or broken wires.
- **Ground Connections: Inspect ground connections for cleanliness and tightness. A poor ground can cause various electrical issues.
- Check for Short Circuits: **Multimeter Testing: Use a multimeter to check for continuity between the potentiometer circuit and ground. If you find continuity where there shouldn’t be, there may be a short circuit.
- **Inspect Circuit: Trace the circuit from the potentiometer to the engine control module (ECM) to identify any points where the wire may be pinched or damaged.
- Test the Potentiometer: **Resistance Check: Measure the resistance of the potentiometer using a multimeter. Compare the readings to the specifications in the vehicle’s service manual. If the resistance is outside the specified range, the potentiometer may be faulty.
- **Functionality Test: If possible, test the potentiometer while moving the throttle pedal to ensure it provides a smooth and consistent signal.
- Check the Servo Motor: **Operation Check: Ensure that the servo motor is functioning correctly. If the motor is not operating as intended, it may need to be replaced.
- **Voltage Supply: Verify that the servo motor is receiving the correct voltage from the ECM.
- Scan for Additional Codes: **Check for Related Codes: Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues.
- Inspect the ECM: **ECM Functionality: If all other components check out, the issue may lie within the ECM itself. Ensure that the ECM is functioning properly and that it is not sending incorrect signals to the servo motor.
- Clear Codes and Test Drive: After performing repairs or replacements, clear the trouble codes using an OBD-II scanner and take the vehicle for a test drive to see if the code returns.
- Consult Service Manual: Refer to the vehicle’s service manual for specific diagnostic procedures and specifications related to the B1279 code and the components involved.
- Professional Help: If the issue persists after following these steps, consider seeking assistance from a professional mechanic or technician who has experience with electronic throttle control systems. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1279 code.