Electrical and sensors

P0571 — Brake Switch / Cruise Control Circuit Malfunction

Severity: medium Safe to drive

What P0571 means

The engine control module monitors the brake pedal switch so it knows when you press the brake. Cruise control uses that signal to cancel when you brake. P0571 sets when the signal is missing, erratic or does not match what the module expects.

Symptoms

  • Cruise control will not set
  • Cruise control does not cancel when braking
  • Brake lights not working or staying on
  • Check Engine light on
  • Shift lock release problems on some vehicles

Possible causes

  1. Failed brake light switch at the pedal
  2. Switch out of adjustment, including on adjustable pedal setups
  3. Damaged, corroded or open wiring near the brake pedal
  4. Poor connection at the switch connector
  5. Faulty second switch contact or cruise control switch
  6. Rarely, a faulty PCM

How to diagnose

  1. Scan for other codes, especially brake or cruise related ones
  2. Check that the brake lights work when pressing the pedal and are off when released
  3. Inspect the switch, connector and harness at the pedal for damage and corrosion
  4. Check the switch position and adjustment relative to the pedal
  5. Watch the brake switch status in scan tool live data while pressing the pedal
  6. Test power, ground and switch continuity with a multimeter using the wiring diagram
  7. Check the brake light fuse
  8. If the switch and wiring are good, test the PCM

Common fixes

  • Replace the brake light switch
  • Adjust the switch position
  • Repair wiring and clean or replace the connector
  • Replace a blown fuse
  • Replace the PCM as a last resort

P0571 on different brands

Ford · manuals
Ford documents an extended P0571:96 for its 2024-2025 gasoline engines, meaning a brake switch A/B correlation fault; it names the monitor condition detected, not a confirmed failed part.

Questions and answers

Can I drive with a P0571 code?

Usually yes, but cruise control may not work. If the brake lights fail to come on when you brake, do not drive until it is repaired.

Why won't my cruise control work with P0571?

The module cannot trust the brake signal, so it disables cruise control as a safety measure. It normally works again once the circuit is repaired.

What most often causes P0571?

The brake light switch on the pedal is the usual culprit, from wear or poor adjustment. Wiring and connector problems come next.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.