Description of the P0566 fault code.
OBD2 Error Codes

P0566 Cruise control off signal fault

26.05.2022 /

P0566 – OBD-II Trouble Code Technical Description

Trouble code P0566 indicates that the PCM has detected a malfunction related to the cruise control system off signal.

What does the fault code mean P0566?

Trouble code P0566 indicates that the engine control module (PCM) has detected a malfunction in the cruise control system disable signal. This means that the PCM is not receiving the correct or expected signal to turn off cruise control, which can result in cruise control not working or not functioning properly. The cruise control system automatically adjusts the vehicle's speed in accordance with commands, and if a problem occurs with the cruise control system, the entire system performs a self-diagnosis.

Fault code P0566.

Possible reasons

Some of the possible causes of the P0566 trouble code are:

  • Multi-function cruise control switch malfunction: Mechanical damage or electrical problems in the multifunction switch can cause P0566.
  • Problems with wiring or connections: Opens, corrosion or poor connections in the wiring connecting the multi-function switch to the PCM can cause an error.
  • Malfunctions in the PCM: Problems with the engine control module itself, such as software glitches or electrical problems, can cause the P0566 code.
  • Problems with other components of the cruise control system: Malfunctions or malfunctions of other components of the cruise control system, such as speed sensors or throttle actuator, can also cause this error.
  • Electrical noise or overload: External factors such as electrical noise or overload may temporarily disturb the signals from the multi-function switch and cause an error.
  • Switching problems within the cruise control system: Faults in the switching mechanisms within the cruise control system may result in incorrect cruise control deactivation signals.
  • Incorrect settings or calibration of the cruise control system: Incorrect settings or calibration of cruise control system components can result in P0566.

To accurately determine the cause of error P0566, it is recommended to conduct detailed diagnostics using specialized equipment and tools.

What are the symptoms of a fault code? P0566?

Symptoms for DTC P0566 may include the following:

  • Cruise control not working: The main symptom is that the cruise control stops working or refuses to activate when you try to turn it on.
  • Inactive cruise control button: The cruise control button on the steering wheel may be inactive or unresponsive.
  • Inactive cruise control indicator: The cruise control indicator on the instrument panel may not light up when you try to activate the cruise control.
  • Dashboard error: Error messages may appear on the instrument panel, such as “Check Engine” or specific indications related to the cruise control system.
  • Uneven speed: When using cruise control, the vehicle speed may change unevenly or erratically.
  • Losing control of speed: The driver may find that the vehicle does not maintain the set speed when using cruise control.

These symptoms may occur to varying degrees depending on the specific cause of the P0566 code and the characteristics of the vehicle. If you notice these symptoms, it is recommended that you contact a professional auto mechanic to diagnose and fix the problem.

How to diagnose a fault code P0566?

To diagnose DTC P0566, you can follow these steps:

  1. Checking Error Codes: Use a diagnostic scan tool to read error codes from the engine management system. Verify that the P0566 code is indeed present.
  2. Visual inspection: Inspect the multi-function cruise control switch and its surroundings for visible damage, corrosion or other problems.
  3. Checking electrical connections: Check the electrical connections connecting the multifunction switch to the PCM. Pay attention to any breaks, corrosion or poor connections.
  4. Multifunction Switch Testing: Use a multimeter to test each of the multifunction switch contacts for the correct resistance or shorts. Compare the results with the manufacturer's recommended values.
  5. PCM diagnostics: If other causes have been ruled out, there may be a problem with the PCM itself. In this case, additional diagnostics will be required to determine its serviceability.
  6. Checking other cruise control system components: Check other components of the cruise control system, such as speed sensors or throttle actuator, to see if they are contributing to P0566.
  7. Software check: Check PCM software for updates or errors. Update or reprogram the PCM as necessary.
  8. Consultation with professionals: If you are unsure of your vehicle diagnostic and repair skills, it is recommended that you contact a professional auto mechanic or service center for further assistance.

After diagnosing and determining the cause of the problem, you can begin the necessary repair actions.

Diagnostic errors

When diagnosing DTC P0566, the following errors may occur:

  • Skipping a visual inspection: Failure to conduct a thorough visual inspection of the multifunction switch and its surroundings may result in obvious problems such as damage or corrosion being missed.
  • Insufficient checking of electrical connections: Skipping a check on electrical connections can lead to misidentification of the problem, especially if the cause of the error is due to poor connections or breaks in the wiring.
  • Faulty multimeter: Using a faulty or uncalibrated multimeter may produce incorrect results when testing resistance or shorts on a multifunction switch.
  • Misinterpretation of scanner data: Inexperienced technicians may misinterpret the data received from the diagnostic scanner, which can lead to incorrect diagnosis and repairs.
  • Ignoring other potential causes: Malfunctions related to other components of the cruise control system or PCM can result in a P0566 code, but can be easily missed when focusing narrowly on one component.
  • Faulty PCM Diagnostics: If possible problems with the PCM itself are not considered, this may result in the need for re-diagnosis after replacing other components.

To avoid these errors, it is important to carry out a comprehensive diagnosis by following standard procedures and using the correct equipment. If in doubt or uncertainty, it is best to contact an experienced auto mechanic or diagnostic specialist.

How serious is the fault code? P0566?

Trouble code P0566 is not a safety critical code, but its severity depends on how important the cruise control function in your vehicle is to you.

In most cases, when the cruise control does not work due to the P0566 code, it can lead to convenient inconvenience for the driver, especially during long highway trips or when maintaining a constant speed.

However, it's worth remembering that the P0566 code could be a sign of a more serious problem with your vehicle's electrical system, including problems with the PCM or other components of the cruise control system. If this problem remains unresolved, it can lead to additional inconvenience and repair costs in the future.

Therefore, although the P0566 code is not an emergency, it is recommended that you take steps to diagnose and resolve this error in order to restore normal cruise control functionality and prevent possible consequences in the future.

What repair will help eliminate the code? P0566?

The repair to resolve the P0566 code will depend on the specific cause of this error, some of the possible actions that may help are:

  1. Replacing the multi-function cruise control switch: If the cause of the error is due to a malfunction or damage to the multi-function switch, you can replace it with a new one.
  2. Checking and repairing electrical connections: Diagnose the electrical circuits connecting the multifunction switch to the PCM. Repair or replace damaged wires and loose connections.
  3. PCM replacement: If other causes have been ruled out, there may be a problem with the engine control module (PCM) itself. In this case, the PCM will need to be replaced or reprogrammed.
  4. Updating the softwareNote: Reprogramming the PCM to the latest software may help resolve the problem if the error was caused by a software glitch.
  5. Diagnosis and replacement of other components of the cruise control system: Check other cruise control system components, such as speed sensors or throttle actuator, and replace them if necessary.
  6. Consultation with professionals: If you are unsure of your vehicle diagnostic and repair skills, it is recommended that you contact a professional auto mechanic or service center for further assistance.

The exact repair to resolve the P0566 code will depend on the specific cause of the error, which requires diagnosis and analysis by a specialist.

How to Diagnose and Fix P0566 Engine Code - OBD II Trouble Code Explain

P0566 – Brand-specific information

Trouble code P0566 can apply to various makes of cars, several of them with explanations:

Determining specific information on the P0566 code for a specific vehicle make may require referring to specialized repair manuals or dealer service.

Add a comment