Fault code P1525 – a step-by-step guide to diagnosing and fixing it

Error code P1525 is displayed and the check engine light is on - what does this mean?

The DTC P1525 is a manufacturer-specific fault code that is recognized by the OBD system and typically indicates problems with the throttle control or the electronic accelerator pedal. This trouble code mainly occurs in Ford, Mazda and other vehicles and indicates faults in the electronic throttle valve system.

What can cause this error code?

• Defective throttle valve actuator
• Dirty or jammed throttle valve
• Damaged accelerator pedal or accelerator pedal position sensor
• Faulty wiring in the throttle valve system
• Defective engine control unit (ECM/PCM)
• Loose or corroded plug connections
• Defective throttle position sensor
• Problems with the power supply

What symptoms occur in parallel with fault code P1525?

• Loss of engine power: Reduced acceleration and poor throttle response
• Irregular idling: Engine runs unevenly or stalls at idling speed
• Starting problems: Difficulty starting the engine
• Emergency running program: Vehicle switches to emergency running mode with limited power
• Delayed throttle response: Response time between accelerator pedal actuation and engine response is increased
• Jerking when accelerating: Uneven power transmission during load changes

How can the problem with fault code P1525 be rectified?

• Repairing fault code P1525 requires a systematic diagnosis of the electronic throttle valve control.
• Clean the throttle valve: Remove the throttle body and clean it thoroughly with a special throttle body cleaner to remove debris
• Replace accelerator pedal position sensor: Replace the defective accelerator pedal position sensor with a new original part and carry out a basic adjustment
• Replace throttle valve actuator: Replace the complete throttle position actuator including the position sensor and program the new part on the vehicle
• Repair wiring: Check all wiring connections between the accelerator pedal, throttle body and control unit and repair any damaged wiring
• Replace engine control unit: If the ECM/PCM is faulty, the control unit must be replaced and reprogrammed
• Clean plug connections: Clean all electrical connections in the system, treat with contact spray and tighten firmly