Fault code P1189 – a step-by-step guide to diagnosing and fixing it

Error code P1189 is displayed and the check engine light is on - what does this mean?

The DTC P1189 is a manufacturer-specific error code that is recognized by the OBD system and indicates a problem with the fuel pressure control system. This trouble code mainly occurs in Volkswagen, Audi, Seat and Skoda vehicles and indicates a fault in the fuel pressure regulator or its control circuit.

What causes can this error code have?

• Defective fuel pressure regulator
• Damaged or corroded cable to the pressure regulator
• Loose or oxidized plug connections
• Defective fuel pump
• Clogged fuel filter
• Faulty engine control unit (ECU)
• Vacuum hose leak on the pressure regulator
• Defective fuel pressure sensor

What symptoms occur in parallel with fault code P1189?

• Starting problems: The vehicle is difficult to start or does not start at all
• Irregular idling: The engine runs irregularly or stutters when idling
• Loss of power: Noticeable reduction in engine power while driving
• Increased fuel consumption: Significant increase in fuel consumption
• Engine misfires: Jerking or misfiring at various engine speeds
• Exhaust problems: Black smoke from the exhaust or increased emission values

How can I fix the problem with fault code P1189?

• Repairing fault code P1189 requires a systematic diagnosis of the fuel system.
• Replace the fuel pressure regulator and check the fuel pressure with a pressure gauge
• Check all cable connections to the pressure regulator for corrosion and damage and replace if necessary
• Clean plug connections, treat with contact spray and connect firmly
• Test the fuel pump and replace it completely if the delivery rate is insufficient
• Replace the fuel filter and check the entire fuel line for blockages
• Check the vacuum hoses on the pressure regulator for cracks and leaks and replace them
• Read out engine control unit with diagnostic device and repair or replace if defective