Resolving P0566 Cruise Control On Signal Malfunction

Cruise control is a convenient feature in modern vehicles that allows drivers to maintain a constant speed without the need to continuously press the accelerator pedal. It offers comfort and reduces fatigue during long drives.

However, like any other automotive system, cruise control can experience malfunctions.

One such issue is the P0566 error code, indicating a cruise control on signal malfunction.

In this article, we will explore the causes, symptoms, diagnosis, and repair of the P0566 error code, providing you with valuable insights to resolve the issue.

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I. Understanding Cruise Control

Cruise control is an automated system that allows drivers to set and maintain a desired speed without intervention.

It is particularly useful on highways and long stretches of road.

When engaged, the cruise control system takes over the throttle control, maintaining a constant speed set by the driver. This feature not only provides convenience but also helps improve fuel efficiency and reduces driver fatigue during extended trips.

II. Common Symptoms of P0566 Error

When the P0566 error code is triggered, several symptoms may manifest, indicating a cruise control on signal malfunction. These symptoms include:

  1. Erratic behavior of the cruise control system: The cruise control may engage or disengage unexpectedly, leading to speed fluctuations.
  2. Warning light illumination: The vehicle’s dashboard may display a cruise control warning light, indicating a fault in the system.
  3. Speed fluctuations: The vehicle’s speed may fluctuate or become inconsistent when cruise control is engaged, making it challenging to maintain a constant speed.

III. Causes of P0566 Error

The P0566 error code can be caused by various factors, including:

  1. Faulty cruise control switch: A malfunctioning switch can disrupt the communication between the driver’s input and the cruise control system.
  2. Malfunctioning brake pedal position sensor: The brake pedal position sensor plays a crucial role in cruise control operation. If it fails or malfunctions, it can trigger the P0566 error code.
  3. Electrical issues or wiring problems: Loose connections, damaged wires, or electrical issues within the cruise control system can lead to the error code.

IV. Diagnosing P0566 Error

To diagnose the P0566 error code, several steps can be taken, including:

  1. Use of diagnostic tools and

scanners: A professional automotive diagnostic scanner can be used to retrieve the specific error code and gather additional information about the cruise control system.

  1. Inspecting the cruise control system components: Thoroughly examine the cruise control switch, wiring, and connectors for any visible damage or loose connections.
  2. Conducting voltage and resistance tests: Use a multimeter to measure the voltage and resistance across various components of the cruise control system. This helps identify any faulty or malfunctioning parts.

V. Repairing P0566 Error

Once the cause of the P0566 error code has been determined, appropriate repairs can be carried out. The following steps may be involved in resolving the issue:

  1. Replacing faulty cruise control switch: If the cruise control switch is found to be defective, it needs to be replaced with a new one. This typically involves removing the steering column cover and disconnecting the switch before installing the new switch.
  2. Repairing or replacing the brake pedal position sensor: If the brake pedal position sensor is causing the error code, it may need to be repaired or replaced. The exact procedure depends on the specific vehicle and sensor design.
  3. Resolving electrical or wiring issues: In cases where the error code is triggered by electrical problems or wiring issues, it is crucial to identify the specific problem area and repair any damaged wires or connections. This may require the expertise of a professional auto electrician.

VI. Prevention and Maintenance Tips

To prevent the recurrence of the P0566 error code and ensure the smooth functioning of the cruise control system, the following maintenance tips are recommended:

  1. Regular inspection and maintenance of the cruise control system: Periodically check the cruise control components, including the switch, wiring, and connectors, for any signs of wear, damage, or corrosion. Clean and lubricate the switch if necessary.
  2. Keeping the brake pedal position sensor clean and functional: Ensure that the brake pedal position sensor is free from dirt, debris, or obstruction. Clean it gently if needed. If the sensor is damaged or malfunctioning, consider replacing it.
  3. Ensuring proper electrical connections: Check the electrical connections associated with the cruise control system. Ensure they are securely fastened and free from corrosion. Repair or replace any damaged wires or connectors.

VII. Conclusion

The P0566 error code indicating a cruise control on signal malfunction can be an inconvenience for vehicle owners. However, by understanding the causes, symptoms, and diagnostic procedures, it becomes easier to address the issue. Whether it’s replacing a faulty switch, repairing the brake pedal position sensor, or resolving electrical problems, taking appropriate measures can restore the proper functioning of the cruise control system. Regular maintenance and inspections play a vital role in preventing such errors and ensuring a pleasant driving experience.


  1. What other error codes are related to cruise control malfunctions?
    • Some related error codes include P0565 (Cruise Control On Signal Malfunction), P0571 (Cruise Control/Brake Switch A Circuit Malfunction), and P0581 (Cruise Control Multi-Function Input “A” Circuit High).
  2. Can I still drive my vehicle with the P0566 error code?
    • While it is technically possible to drive the vehicle with the error code, it is recommended to have the issue diagnosed and repaired to avoid potential safety risks and further damage to the cruise control system.
  3. Is it possible to fix the P0566 error code without professional help?
    • Depending on your automotive knowledge and experience, some repairs related to the P0566 error code can be performed by yourself. However, for complex issues or if you are unsure, it is recommended to seek professional assistance to ensure proper diagnosis and repair.