The P0571 code is a generic powertrain code that indicates a problem with the cruise control brake switch circuit. When your vehicle’s onboard diagnostic system detects an issue with the brake switch that deactivates the cruise control, it will trigger this code. Understanding and resolving this issue is crucial for maintaining your vehicle’s safety features and ensuring proper cruise control operation.
| P0571 Code Meaning | P0571 Code Common Causes |
|---|---|
| Cruise Control Brake Switch A Circuit Malfunction | Faulty brake switch |
| Issue with the switch that deactivates cruise control | Damaged or corroded wiring |
| Problem in the brake switch circuit | Blown fuse |
| Malfunction in the cruise control system | Misadjusted brake switch |
| Error in the powertrain control module (PCM) | PCM software issues |
Understanding the P0571 Code
The P0571 code specifically relates to the cruise control brake switch circuit. This switch is responsible for disengaging the cruise control when the brake pedal is pressed. It’s a critical safety feature that ensures the vehicle doesn’t continue to accelerate when you’re trying to slow down or stop.
Symptoms of a P0571 code may include:
- Illuminated check engine light
- Cruise control not functioning
- Cruise control engaging or disengaging erratically
- Brake lights not working properly
When the powertrain control module (PCM) detects an abnormal voltage in the brake switch circuit, it will set the P0571 code. This could be due to an open circuit, short circuit, or an out-of-range voltage reading.
Diagnosing the P0571 Code
Proper diagnosis of the P0571 code requires a systematic approach. Here’s a step-by-step guide to help you identify the root cause:
- Connect an OBD-II scanner to verify the P0571 code and check for any additional codes.
- Inspect the brake switch and its wiring for visible damage or corrosion.
- Check the brake light fuse and replace if blown.
- Test the brake switch using a multimeter to ensure it’s functioning correctly.
- Examine the wiring harness for any signs of wear, damage, or loose connections.
- Verify the brake switch adjustment to ensure it’s making proper contact.
- Use a scan tool to monitor the brake switch input while operating the brake pedal.
- If all physical components check out, consider potential PCM software issues.
It’s important to note that while some of these steps can be performed by DIY mechanics, others may require professional diagnostic equipment and expertise.
Fixing the P0571 Code
Once you’ve identified the cause of the P0571 code, you can proceed with the appropriate fix. Here are some common solutions:
- Replacing the Brake Switch:
If the brake switch is faulty, replacing it is often the most straightforward solution. This typically involves:
- Locating the brake switch near the brake pedal
- Disconnecting the electrical connector
- Removing the old switch
- Installing the new switch and ensuring proper adjustment
- Reconnecting the electrical connector
Cost estimate: $50 to $150, depending on the vehicle make and model.
- Repairing Wiring Issues:
If damaged wiring is the culprit, you’ll need to:
- Locate the damaged section of wiring
- Cut out the damaged portion
- Splice in new wiring using appropriate connectors
- Insulate the repair with heat-shrink tubing
Cost estimate: $50 to $200, depending on the extent of the damage and labor costs.
- Adjusting the Brake Switch:
If the brake switch is misadjusted, you can:
- Locate the brake switch mounting bracket
- Loosen the mounting nuts
- Adjust the switch position
- Tighten the mounting nuts
- Test the brake switch operation
Cost estimate: $0 to $100, depending on whether you do it yourself or have a professional adjust it.
- Updating PCM Software:
If a software issue is suspected, you’ll need to:
- Visit a dealership or specialized automotive shop
- Have them update the PCM software
- Verify that the update resolves the issue
Cost estimate: $100 to $300, depending on the dealership and vehicle model.
Warning: Always disconnect the vehicle’s battery before working on electrical components to avoid short circuits or electrical shocks.
Preventing Future P0571 Codes
To minimize the chances of encountering the P0571 code in the future, consider these preventive measures:
- Regular Maintenance:
Perform routine checks on your vehicle’s electrical system, including the brake switch and associated wiring. - Protect Wiring:
Shield wiring harnesses from heat sources and moving parts to prevent damage. - Keep Connections Clean:
Regularly clean electrical connections to prevent corrosion and ensure good contact. - Address Issues Promptly:
Don’t ignore warning lights or unusual behavior in your vehicle’s cruise control system. - Use Quality Parts:
When replacing components, opt for high-quality, OEM or equivalent parts to ensure longevity and proper function.
When to Seek Professional Help
While many aspects of diagnosing and fixing a P0571 code can be handled by experienced DIY mechanics, there are situations where professional assistance is recommended:
- If you lack the necessary diagnostic tools or expertise
- When dealing with complex electrical issues or intermittent problems
- If the code persists after attempting common fixes
- When PCM software updates are required
- If you’re uncomfortable working with your vehicle’s electrical system
Professional mechanics have access to advanced diagnostic equipment and manufacturer-specific information that can streamline the troubleshooting process.
Conclusion
The P0571 code, while not typically causing immediate drivability issues, should not be ignored. It indicates a problem with a crucial safety feature of your vehicle. By understanding the causes, symptoms, and solutions for this code, you can take appropriate action to maintain your vehicle’s safety and performance. Remember, when in doubt, it’s always best to consult with a certified automotive technician to ensure the issue is properly resolved.
Frequently Asked Questions About P0571
- Can I drive my car with the P0571 code?
While the vehicle may still be drivable, it’s not recommended to continue driving with this code active. The cruise control system may malfunction, potentially creating unsafe driving conditions. - Will the P0571 code clear itself?
In most cases, the code will not clear itself. You’ll need to fix the underlying issue and then use an OBD-II scanner to clear the code. - How often should I check my brake switch?
It’s a good practice to have your brake switch checked during regular maintenance, typically every 12,000 to 15,000 miles. However, if you notice any issues with your cruise control or brake lights, check it immediately. - Can a bad brake light cause the P0571 code?
While a bad brake light itself typically won’t cause the P0571 code, the underlying issue causing the brake light failure (such as a faulty switch or wiring problem) could trigger the code. - Is the P0571 code specific to certain vehicle makes?
No, P0571 is a generic powertrain code that can appear in various vehicle makes and models equipped with OBD-II systems and cruise control. - Can extreme weather conditions trigger the P0571 code?
Extreme temperatures or moisture can potentially affect electrical components and connections, which might indirectly lead to a P0571 code. However, this is not a common direct cause. - How long does it take to fix a P0571 code?
The time to fix a P0571 code can vary greatly depending on the underlying cause. Simple fixes like replacing a brake switch might take 30 minutes to an hour, while more complex wiring issues could take several hours. - Can a P0571 code affect my vehicle’s fuel efficiency?
Generally, a P0571 code doesn’t directly impact fuel efficiency. However, if the issue causes the cruise control to malfunction, it might indirectly affect fuel consumption, especially during highway driving.