Fault code P1571 – a step-by-step guide to diagnosing and fixing it

Error code P1571 is displayed and the check engine light is on - what does this mean?

The DTC P1571 is a manufacturer-specific fault code that is recognized by the OBD system and typically indicates problems with the brake pedal position or the brake system interface. This trouble code mainly occurs in Ford vehicles and indicates a fault in the communication between the brake pedal position sensor and the engine control unit.

What can cause this error code?

• Defective brake pedal position sensor
• Damaged wiring harness to the brake pedal position sensor
• Loose or corroded plug connections
• Incorrect calibration of the brake pedal position sensor
• Defective brake switch or brake light switch
• Problems with the vehicle wiring
• Faults in the engine control unit (ECM/PCM)
• Mechanical damage to the brake pedal

What symptoms occur in parallel with fault code P1571?

• Check engine light: The check engine light is permanently activated
• Starting problems: The vehicle may not start or shows delayed starting response
• Idling problems: Unsteady idling or fluctuating engine speeds
• Brake light malfunctions: Brake lights not working properly
• Cruise control failure: Cruise control no longer works
• Shifting problems: Shifting problems may occur with automatic transmissions

How to fix the problem of error code P1571?

• Repairing EOBD error code P1571 requires systematic diagnosis and targeted measures.
• Replace the brake pedal position sensor completely and then have it recalibrated
• Check the wiring harness to the brake pedal for damage and replace defective cables
• Clean and check all plug connections on the brake pedal and replace if corroded
• Remove brake light switch, test and replace with new component if defective
• Reprogram the engine control unit with the latest software or replace if hardware is defective
• Completely recalibrate the brake pedal position sensor with diagnostic device
• Check fuses and relays in the brake system circuit and replace defective components