Technical Description of OBD-II Trouble Code
The Cruise Control Input Circuit is experiencing a low voltage condition.
What does that mean?
This is a generic powertrain diagnostic trouble code (DTC) that is commonly found in OBD-II vehicles equipped with cruise control. This code can be applicable to various vehicle makes such as Chevrolet (Chevy), Toyota, Ford, Harley, Dodge, Ram, Ford, etc.
The ECM (Engine control module) is responsible for ensuring that the engine operates properly while maintaining acceptable levels of emissions, fuel economy, performance, and comfort functions. Cruise control is a convenient feature for long trips as it allows the vehicle’s speed to be controlled automatically. However, if the cruise control system has any defects, the ECM may disable it. One indication of a complete disablement is the absence of the cruise control light on the dashboard when attempting to activate it.
In general, this trouble code indicates an electrical malfunction in the control input circuit. The P0576 Cruise Control Input Circuit Low and related codes (P0575 and P0577) are set when the ECM detects a low voltage condition in the cruise control input circuit.
Cruise control switches:
What is the severity of this DTC?
This particular code is considered a mild issue that does not require immediate repair. The engine performance will not be affected, allowing the vehicle to remain operational. The main problem associated with this code is the inability to use the cruise control function.
However, it is important to note that when the ECM displays a P0576 or any other P code, the vehicle may not pass an emissions test. Therefore, it is crucial to clear the code after every repair before undergoing a retest. Failing to do so may prevent the mechanic from accurately identifying the problem, potentially leading to more serious issues in the future.
What are some of the symptoms of the code?
The most common symptom of the P0576 code is the malfunction or complete failure of the cruise control system. Other possible symptoms include:
What are some of the common causes of the code?
The causes of the P0576 cruise control code may include:
What are some P0576 diagnostic and troubleshooting steps?
The first step in troubleshooting any malfunction is to consult the Technical Service Bulletins (TSB) for known issues with the specific vehicle.
Advanced diagnostic steps will vary depending on the vehicle and may require specialized equipment and knowledge. The following basic steps are provided as a general guideline, but it is recommended to refer to a vehicle-specific repair guide for detailed instructions.
Basic Step #1
After recording the active P0576 code with an OBD-II DTC scanner, thoroughly inspect the vehicle’s connectors, wiring, and other components of the cruise control system. Replace, reconnect, or repair any damaged connectors, such as those with broken tabs, heat damage, or corrosion. Clear the code and perform a short test drive to check if the cruise control functions properly. If the repair is successful, ensure that the check engine light no longer reappears. If the light does come back on and the code is stored in the ECM again, continue with further diagnostics.
Basic Step #2
Test the cruise control switch (also known as the multifunction switch) according to the procedures and desired values specified in the vehicle’s service manual. This may involve using a digital volt-ohm meter (DVOM) to measure electrical values. Compare the actual values to the manufacturer’s desired values to determine if the switch is the cause of the issue or if it can be ruled out.
Basic Step #3
If the switch is found to be defective, replacing it may require removing steering column covers, especially if there are airbags in the way. Follow the specific steps provided in the vehicle’s manual to replace the switch. After replacing the switch, test drive the vehicle and clear any active codes.
This article is intended for informational purposes only, and it is always recommended to prioritize the technical data and service bulletins specific to your vehicle.
