The P0568 diagnostic trouble code (DTC) signifies a malfunction in the cruise control set signal circuit. This code indicates that the vehicle's computer has detected an issue with the signal sent when the cruise control "set" button is pressed. Addressing this problem promptly is crucial for restoring full cruise control functionality and ensuring a safer driving experience.
The cruise control system relies on various inputs, including the set signal, to maintain a consistent speed. A faulty set signal can prevent the system from engaging or maintaining the desired speed, rendering the cruise control inoperable. This article will delve into the causes, symptoms, diagnosis, and potential solutions for a P0568 code.
| Category | Description | Potential Impact |
|---|---|---|
| Possible Causes | Faulty Cruise Control Switch: A worn or damaged switch can fail to send the correct signal. Wiring Issues: Damaged, corroded, or shorted wires in the cruise control circuit. Connector Problems: Loose or corroded connectors in the cruise control system. Clock Spring Malfunction: The clock spring, located in the steering column, provides electrical connection to the steering wheel controls and can fail. Faulty Powertrain Control Module (PCM): Rarely, the PCM itself may be the source of the problem. Brake Light Switch Issues: The brake light switch is integrated with the cruise control system and can cause issues if malfunctioning. | Loss of Cruise Control Functionality: The primary impact is the inability to engage or maintain cruise control. Intermittent Cruise Control Operation: The system may work sometimes and not others. Potential Safety Concerns: In rare cases, a malfunctioning cruise control system could lead to unintended acceleration or deceleration. Increased Fuel Consumption: Driving without cruise control can lead to inconsistent speed and potentially higher fuel consumption. |
| Symptoms | Cruise Control Inoperative: The most obvious symptom is the inability to activate the cruise control system. Cruise Control Does Not Set: The system may engage but fails to maintain the set speed. Intermittent Cruise Control Function: The system works sporadically. Cruise Control Light Does Not Illuminate: The cruise control indicator light on the dashboard may not turn on when the system is engaged. Other Warning Lights: In some cases, other warning lights related to the engine or transmission may illuminate. | Driver Frustration: The inability to use cruise control can be frustrating for drivers, especially on long trips. Reduced Driving Comfort: Cruise control enhances driving comfort by reducing driver fatigue. Potential for Speeding Tickets: Without cruise control, drivers may inadvertently exceed the speed limit. |
| Diagnostic Steps | Visual Inspection: Check the cruise control switch, wiring, and connectors for any signs of damage or corrosion. Scan Tool Diagnosis: Use a scan tool to retrieve the P0568 code and any other related codes. Cruise Control Switch Testing: Test the cruise control switch using a multimeter to ensure it is functioning correctly. Wiring Harness Testing: Check the wiring harness for continuity and shorts using a multimeter. Clock Spring Inspection: Inspect the clock spring for damage or wear. Brake Light Switch Testing: Test the brake light switch for proper operation. PCM Testing: As a last resort, test the PCM to rule out any internal faults. | N/A |
Detailed Explanations
Faulty Cruise Control Switch: The cruise control switch, typically located on the steering wheel or stalk, is responsible for sending the "set" signal to the vehicle's computer. Over time, the switch can wear out, become damaged, or develop internal faults, preventing it from sending the correct signal. This can cause the P0568 code to be triggered.
Wiring Issues: The wiring harness connecting the cruise control switch to the vehicle's computer is susceptible to damage from environmental factors, such as heat, moisture, and vibration. Damaged, corroded, or shorted wires can disrupt the flow of the set signal, leading to the P0568 code. Thorough inspection and repair of any wiring issues are crucial for resolving this problem.
Connector Problems: Loose or corroded connectors in the cruise control system can also interfere with the set signal. Corrosion can build up on the connector terminals, creating resistance and preventing the signal from reaching its destination. Loose connectors can cause intermittent connection problems, leading to sporadic cruise control operation.
Clock Spring Malfunction: The clock spring, located in the steering column, is a coiled ribbon cable that allows electrical connections to be maintained to the steering wheel controls while the steering wheel is turned. A damaged or broken clock spring can interrupt the set signal, triggering the P0568 code. Replacing the clock spring is often necessary to resolve this issue.
Faulty Powertrain Control Module (PCM): While less common, the PCM itself can be the source of the P0568 code. The PCM is the vehicle's main computer and controls various functions, including cruise control. If the PCM has an internal fault in the cruise control circuit, it may misinterpret or fail to process the set signal. This is usually diagnosed after ruling out all other potential causes.
Brake Light Switch Issues: The brake light switch is integrated with the cruise control system as a safety feature. When the brake pedal is pressed, the brake light switch sends a signal to the PCM to disengage the cruise control. If the brake light switch is faulty and sending an incorrect signal, it can interfere with the cruise control's ability to set or maintain speed, potentially leading to the P0568 code.
Cruise Control Inoperative: This is the most direct symptom. The cruise control system simply will not turn on or engage when you attempt to activate it. No amount of pressing the "on" or "set" buttons will result in the system engaging.
Cruise Control Does Not Set: The cruise control system might turn on and the indicator light might illuminate, but when you press the "set" button, the vehicle will not maintain the current speed. It might decelerate or simply ignore the command.
Intermittent Cruise Control Function: The system may work sometimes, but not others. This can be particularly frustrating, as it makes it difficult to rely on the cruise control system. The intermittent nature of the problem often points to a loose connection or a wiring issue that is affected by vibration or temperature.
Cruise Control Light Does Not Illuminate: When the cruise control system is engaged, a light on the dashboard typically illuminates to indicate that the system is active. If this light does not turn on, it can be a sign of a problem with the cruise control system, potentially related to the set signal.
Other Warning Lights: In some instances, a P0568 code can be accompanied by other warning lights on the dashboard. This can be due to the cruise control system sharing circuits or sensors with other vehicle systems.
Visual Inspection: A careful visual inspection of the cruise control switch, wiring, and connectors can often reveal obvious signs of damage, such as broken wires, corroded terminals, or loose connections. This is a crucial first step in the diagnostic process.
Scan Tool Diagnosis: A scan tool is an essential tool for diagnosing automotive problems. It can be used to retrieve the P0568 code and any other related codes that may provide clues about the underlying cause of the problem. The scan tool can also be used to monitor the live data from the cruise control system, which can help pinpoint the source of the malfunction.
Cruise Control Switch Testing: A multimeter can be used to test the cruise control switch for proper operation. The multimeter can be used to check the continuity of the switch contacts when the "set" button is pressed. If the switch is not functioning correctly, it will need to be replaced.
Wiring Harness Testing: The wiring harness can be tested for continuity and shorts using a multimeter. Continuity testing verifies that the wires are intact and that there are no breaks in the circuit. Short testing checks for unwanted connections between wires, which can disrupt the flow of the set signal.
Clock Spring Inspection: A visual inspection of the clock spring can reveal signs of damage or wear. A broken or frayed clock spring will need to be replaced. In some cases, the clock spring can be tested using a multimeter, but this requires specialized knowledge and should only be performed by a qualified technician.
Brake Light Switch Testing: The brake light switch can be tested for proper operation using a multimeter. The multimeter can be used to check the continuity of the switch contacts when the brake pedal is pressed. If the switch is not functioning correctly, it will need to be replaced.
PCM Testing: Testing the PCM is a complex process that requires specialized equipment and knowledge. It should only be performed by a qualified technician. The PCM can be tested to rule out any internal faults in the cruise control circuit.
Frequently Asked Questions
What does the P0568 code mean? The P0568 code indicates a malfunction in the cruise control set signal circuit, meaning the vehicle's computer isn't receiving the correct signal when the "set" button is pressed. This usually results in the cruise control system not working.
Can I still drive my car with a P0568 code? Yes, you can usually still drive your car, but the cruise control system will likely be inoperative. There are generally no immediate safety concerns beyond the loss of cruise control functionality.
How do I fix a P0568 code? The fix depends on the cause, but common solutions include replacing the cruise control switch, repairing damaged wiring, replacing the clock spring, or, in rare cases, replacing the PCM. Proper diagnosis is crucial.
Is the P0568 code serious? The P0568 code is generally not considered serious in terms of immediate safety, but it does indicate a malfunction in a safety-related system. Addressing the problem is important for restoring full functionality and preventing potential future issues.
How much does it cost to fix a P0568 code? The cost to fix a P0568 code can vary widely depending on the cause and the required repairs. Replacing a faulty switch might cost $100-$300, while replacing the clock spring or PCM could be significantly more expensive, potentially exceeding $500.
Conclusion
The P0568 code signifies a malfunction in the cruise control set signal circuit, often resulting in the loss of cruise control functionality. Thorough diagnosis is crucial to identify the underlying cause, which may range from a faulty switch to wiring issues or, less commonly, a PCM problem. Addressing the issue promptly will restore the cruise control system and ensure a safer and more comfortable driving experience.