Fault code P1566 – a step-by-step guide to diagnosing and fixing it

Error code P1566 is displayed and the check engine light is on - what does this mean?

The DTC P1566 is a manufacturer-specific fault code that is recognized by the OBD system when problems occur with the exhaust gas recirculation (EGR) or the cruise control system. This trouble code can have different meanings depending on the vehicle manufacturer, but usually refers to control problems with electronic systems.

What causes can this error code have?

• Defective EGR valve or EGR control module
• Damaged cable in the cruise control system
• Loose or corroded plug connections
• Defective position sensor in the EGR system
• Blocked EGR lines or ducts
• Faulty control unit software
• Defective vacuum lines in the EGR system
• Problems with the throttle valve control

What symptoms occur in parallel with fault code P1566?

• Loss of engine power: Reduced acceleration and reduced top speed
• Irregular idling: Engine runs unevenly or stutters when idling
• Cruise control failure: Cruise control does not work or switches off spontaneously
• Increased exhaust emissions: Poorer emission values during the emissions test
• Starting problems: Difficult starting, especially when the engine is cold
• Jerking while driving: Uneven engine performance while driving

How to fix the problem of fault code P1566?

• Repairing fault code P1566 requires a systematic diagnosis of the affected systems.
• Remove the EGR valve, clean thoroughly or replace completely if defective
• Check all cable connections in the cruise control system and repair damaged cables
• Clean plug connections, use contact spray and ensure tight fit
• Test EGR position sensor and replace with new component if malfunctioning
• Flush clogged EGR channels with special cleaner and remove deposits
• Update the control unit software to the latest version or perform a reset
• Check vacuum lines for cracks and replace leaking hoses
• Clean the throttle body and calibrate the electronic throttle valve