Fault code P0566 is called “Cruise Control Off Signal Malfunction” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.
Technical description and explained code P0566
This diagnostic trouble code (DTC) is a generic code. Error P0566 is considered a generic code because it applies to all makes and models of vehicles. Although the specific repair steps may vary slightly from model to model.
Cruise control was designed for comfort, the sole purpose of which is to maintain the vehicle speed set manually by the driver. The driver does not need to control the accelerator pedal. If the car is equipped with an automatic transmission, he can control and adjust the shifts according to the driving conditions in real time.
This code refers to a specific input circuit in the cruise control system. Refer to your service manual to determine which wire or circuit to focus on. Since the turn signal circuit may vary from manufacturer to manufacturer.
If the cruise control off signal is faulty, the control module (PCM) will write code P0566 into memory and turn on the warning light on the instrument panel. It is likely that after this, the use of this function will be disabled or will not work properly.
Symptoms of vehicle malfunctions
The main signal that an error P0566 has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.
It can also be warning signs such as:
- Cruise control lamp on the dashboard is not lit or is lit constantly.
- Cruise control does not work completely.
- Unstable operation of the cruise control.
- Some functions do not work as they should (e.g. setting, resuming, accelerating, etc.).
- Cruise control turns on but does not work.
- Unable to set the cruise control to the desired speed.
Code P0566 has a low degree of severity, as it does not affect the safety and major components of the car. But, like any electrical problem, it is better to eliminate it, so that the malfunction does not worsen in the future.
Factors that can cause this error code
The error code P0566 can mean that one or more of the following problems have occurred:
- Cruise control switch is defective.
- Wiring problem (breakage, chafing, etc.).
- Faulty connector (e.g. corroded contacts).
- Debris and dirt is mechanically interfering with the cruise control switch.
- Cruise control module is defective.
- Sometimes the cause is a defective PCM module.
How to fix or reset OBD-2 code P0566
Some suggested steps for troubleshooting and fix the error code P0566:
- Usually you only need to repair or replace damaged wires to correct this error.
- It is also necessary to check the connection connectors.
- You should check for debris that is interfering with the cruise control switch.
- If no problems are found, the cruise control module or PCM may be defective.
Diagnose and repair of problems
The first step in troubleshooting P0566 is to review the Technical Service Bulletins (TSB). For known problems with a particular vehicle.
Next, locate the vehicle’s multi-function cruise control switch and visually inspect it for contamination. Plastic buttons get dirty very easily, causing them to not function properly.
Make sure that the mechanical operation of the switch is smooth and uninterrupted. Any problem should be corrected.
To access the connectors and harnesses of the cruise control switch input circuit, you may need to remove the protective plastic. After that, check the continuity of the wires and connections.
A problem with the PCM module is, in most cases, a last resort to diagnose error P0566. Given the fact that this can be one of the most expensive repairs, it’s best to leave it to the professionals.
On which vehicles does this problem occur most frequently
Fault code P0566 can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:
- Ford
- Isuzu
- Volkswagen (Tiguan)
Fault code P0566 can sometimes be found with other errors. The most common are the following: P0564, P0565, P0567, P0568, P0569, P056A, P056B, P0570.
