Error code P1125 is displayed and the check engine light is on - what does this mean?
The DTC P1125 is a manufacturer-specific fault code that is recognized by the OBD/EOBD system and indicates a problem with the throttle actuator or the electronic throttle control. This trouble code mainly occurs in Volkswagen, Audi, Seat and Skoda vehicles and indicates a fault in the throttle valve position or its control.
What causes can this error code have?
- Defective throttle valve actuator
- Dirty or jammed throttle valve
- Damaged throttle potentiometer
- Defective cable connections to the throttle valve actuator
- Faulty engine control unit software
- Loose or corroded plug connections
- Defective throttle sensor
- Mechanical blockage of the throttle valve
- Wear on the throttle valve axle
- Defective power supply to the throttle valve system
What symptoms occur in parallel with fault code P1125?
- Loss of power: The engine shows significantly reduced power and reacts sluggishly to accelerating
- Irregular idling: The engine runs irregularly at idle or even shuts off
- Starting problems: The vehicle is difficult to start or requires several attempts to start
- Emergency running program: The vehicle switches to emergency running mode with limited speed
- Jerking when accelerating: Noticeable irregularities when accelerating, especially under load
- Increased fuel consumption: Significantly increased consumption due to inefficient combustion
How can the problem with fault code P1125 be rectified?
- Repairing fault code P1125 requires a systematic diagnosis and targeted measures to rectify the throttle valve problem.
- Clean the throttle valve: Remove the throttle valve and clean thoroughly with special throttle valve cleaner, then carry out basic adjustment
- Replace throttle valve actuator: Complete replacement of the defective throttle valve actuator including teach-in via diagnostic device
- Check and repair wiring harness: Continuity check of all cables to the throttle actuator and repair of damaged cables or connectors
- Engine control unit update: Software update of the control unit at the authorized dealer to rectify known program errors
- Replace throttle potentiometer: Separate replacement of the position sensor, if this is available separately
- Carry out basic adjustment: After each repair, reprogram and recalibrate the throttle valve using the diagnostic device
FAQ - Frequently asked questions about DTC P1125
Can I continue driving with error code P1125?
Continuing to drive with code P1125 is only possible to a limited extent. The vehicle usually switches to emergency mode, which limits the speed. A prompt repair is strongly recommended, as further damage to the engine may occur.
How much does it cost to repair error code P1125?
The repair costs vary depending on the cause: A throttle valve cleaning costs around 80-150 euros, a new throttle valve actuator between 200-600 euros plus labor. Cable problems can cost between 100-300 euros.
How can I delete the error code P1125 myself?
The DTC P1125 can be deleted with an OBD diagnostic device, but will return if the cause has not been rectified. After a successful repair, the trouble code disappears automatically after several driving cycles.
Is fault code P1125 the same for all manufacturers?
No, P1125 is a manufacturer-specific code that mainly occurs in VAG vehicles (Volkswagen, Audi, Seat, Skoda). Other manufacturers use different codes for similar problems.
How often does error code P1125 occur?
Code P1125 is relatively common in VAG vehicles built after 2000, especially in vehicles with higher mileage. The electronic throttle valve is a wearing part that can cause problems after 100,000-200,000 km.
Can a dirty throttle valve trigger the P1125?
Yes, a heavily contaminated throttle valve is a common cause of EOBD code P1125. Deposits can hinder the movement of the flap and lead to position errors, which the control unit registers as a fault code.