Fault code P1523 – a step-by-step guide to diagnosing and fixing it

Error code P1523 is displayed and the check engine light is on - what does this mean?

The OBD/EOBD system detects a fault in the idle control or throttle valve actuator area. This manufacturer-specific DTC P1523 mainly occurs in Volkswagen, Audi, Seat and Skoda vehicles and indicates problems with the electronic throttle control.

What causes can this error code have?

• Defective throttle valve actuator motor
• Dirty or jammed throttle valve
• Damaged cable connections to the throttle valve actuator
• Faulty throttle valve sensors
• Defective engine control unit
• Loose or corroded plug connections
• Mechanical blockage of the throttle valve
• Vacuum leaks in the intake system

What symptoms occur in parallel with fault code P1523?

• Irregular idling: The engine runs irregularly or fluctuates in speed
• Starting problems: The vehicle is difficult to start or stalls after starting
• Jerking when accelerating: Uneven engine performance when accelerating
• Increased fuel consumption: Significantly higher fuel consumption than usual
• Check engine light: Permanently lit or flashing warning light
• Emergency running program: Reduced engine power and limited top speed

How can the problem with error code P1523 be rectified?

• The repair requires a systematic diagnosis, as several components may be affected.
• Remove the throttle valve, clean thoroughly and check for mechanical free movement, then carry out basic adjustment
• Replace the throttle valve actuator completely and have the new component programmed with the engine control unit
• Check all cable connections and plugs to the throttle valve for damage, repair or replace defective cables
• Test the throttle valve sensors individually and replace the entire throttle valve body if defective
• Check vacuum lines in the intake system for leaks and replace damaged hoses
• Have the engine control unit checked by a specialist workshop and program or replace if defective