P0571Brake Switch A Circuit
- Generic OBD-II code · Powertrain
- How the car detects it
- Brake switch A is the brake light switch or its signal to the engine module. The module needs it to cancel cruise control and for brake-throttle override, stop-start, idle control and the shift interlock. As cruise control is simply switched off, CARB treats such faults as emission-neutral – usually without warning lamp. P0571 is the general fault, usually detected by plausibility: Saab's 3.0 TiD (Bosch) sets it when the car brakes three times from over 49 km/h to standstill at 1.6 m/s² or more without a switch signal; Bosch EDC16 then switches cruise control off. NHTSA found Hyundai and Kia setting P0571 with P0504 from misadjusted brake light switches. Ford and GM petrol engines use P0572/P0573 instead.
- What you may notice
- Cruise control cannot be set or switches off
- Brake lights not working or permanently on
- Possibly ABS/ESC warning (Hyundai/Kia)
- Likely causes
- LikelyBrake light switch misadjusted
- LikelyBrake light switch faulty (worn contact)
- PossibleConnector, wire or brake light fuse
- RareEngine or body module
- Repair
- Easy · Often possible to do yourself.Typical cost: €15 – €120
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.