Technical Description of OBD-II Trouble Code
Malfunction in Cruise Control Set Signal
What does that signify?
This is a generic diagnostic trouble code (DTC) related to the powertrain and is commonly found in OBD-II vehicles equipped with cruise control. This can include vehicles from various manufacturers such as Peugeot, Ford, Nissan, Chevrolet, Hyundai, VW, Audi, Citroen, and others. While the code is generic, the specific repair steps may vary depending on the year, make, model, and powertrain configuration of the vehicle.
The cruise control system in a vehicle offers several functions. It allows the operator to set a specific speed, which can be automatically maintained using various sensors, switches, modules, and other components. Additionally, the speed can be electronically modified (e.g., “set -” and “resume +”), temporarily adjusted for passing vehicles or unexpected slowing/stopping, and more.
Most of the functions mentioned in the description of code P0568, as well as related codes like P0565, P0566, P0567, P0569, P0570, etc., are contained within a single switch/component. Therefore, locating the mechanical inputs (e.g., buttons, switches, talks) involved should be relatively straightforward. Some common names for this component(s) include Multi-function switch, Steering wheel controls, Cruise control switch, Cruise control module, and Accessory switch.
In the case of this code, the Engine Control Module (ECM) has detected a malfunction within the signal circuit. In simple terms, something has gone wrong with the function mentioned in the description.
When the ECM detects a signal malfunction in one or more cruise control functions, it illuminates the Check Engine Light (CEL) and displays the code P0568 or related codes. The use of the affected function(s) will most likely be disabled or behave abnormally.
Code P0568 is triggered when the ECM detects a signal malfunction in the SET signal of the cruise control system.
Here is an example of cruise control buttons on a steering wheel:
What is the severity of this DTC?
The severity of this DTC is considered moderately low. Even if the entire cruise control system loses functionality, it is still possible to safely drive the vehicle. However, neglecting any electrical issue for an extended period may lead to further damage, although this is a rare case where it may be acceptable to neglect the repair if the vehicle is old or if the owner cannot afford to fix it.
Nevertheless, it is important to note that neglecting any electrical issue for too long can potentially result in additional damage.
What are some of the symptoms of the code?
Symptoms of a P0568 trouble code may include:
What are some of the common causes of the code?
The causes of the P0568 code may include:
What are some P0568 troubleshooting steps?
Basic Step #1
Start by visually inspecting the cruise control switch/module. Check for missing buttons, buttons stuck due to cola or other substances, loose buttons that do not make proper electrical connections, and any contamination that could potentially damage the buttons controlling the cruise functions. Make sure to document all malfunctions or abnormalities related to the cruise functions.
Basic Step #2
Verify if the cruise control light in the instrument cluster comes on when the cruise control is manually activated. If the light does not come on, check if there is a fuse dedicated to the cruise control circuit. Consult the vehicle’s service manual for information on the fuse location and replace any blown fuses with new ones approved by the manufacturer.
Basic Step #3
To access the harness leading to the cruise control switch/module, you will likely need to remove certain parts of the dashboard (e.g., steering column shroud, airbag module in the steering wheel, etc.). To identify the specific wire involved in the fault, you will need a proper wiring harness specific to your vehicle. These harnesses can vary significantly, so always consult the appropriate service information before performing any invasive procedures.
Basic Step #4
Ensure that your Anti-lock Braking System (ABS) is in good working order and that no ABS light is illuminated on the dashboard. The ABS system relies on various sensors, including speed sensors. Malfunctioning speed sensors can mislead the vehicle’s computers into thinking that the vehicle is traveling at a different speed than it actually is.
