Cruise Control/Brake Switch A Circuit Malfunction
The P0571 code indicates a malfunction in the cruise control/brake switch A circuit. This switch is typically located on the brake pedal and sends a signal to the powertrain control module (PCM) when the brake is applied. The PCM uses this signal to disengage cruise control and for other safety functions. A fault in this circuit can prevent cruise control from engaging or cause it to disengage unexpectedly.
1. Most Common Causes
- Faulty brake switch
- Misadjusted brake switch
- Blown fuse or faulty relay
- Wiring or connector issues in the brake switch circuit
2. Symptoms You Will Notice
- Cruise control inoperative
- Cruise control disengages unexpectedly
- Brake lights may not work properly
- Check Engine Light illuminated
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for other related codes.
Step 2: Visually inspect the brake switch for proper adjustment and operation; check for broken or loose wiring.
Step 3: Test the brake switch with a multimeter for continuity when the pedal is pressed and released.
Step 4: Check the fuse and relay for the brake switch circuit; replace if blown.
Step 5: If all else fails, replace the brake switch and clear the code.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe to drive, but cruise control will not work. However, if the brake lights are also affected, it could be a safety concern. It's best to diagnose and fix the issue promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150, including parts and labor. A brake switch costs around $20-$50, and labor is usually minimal.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.