P0571 code meaning
Brake Switch A Circuit
What P0571 means
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 gasoline engines use P0572/P0573 instead.
P0571 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.3 to 1 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0571
- Cruise control cannot be set or switches off
- Brake lights not working or permanently on
- Possibly ABS/ESC warning (Hyundai/Kia)
Common causes of P0571
- Most likelyBrake light switch misadjusted
- Most likelyBrake light switch faulty (worn contact)
- PossibleConnector, wire or brake light fuse
- Less likelyEngine or body module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Brake switchBrake light fuseSwitch wiringEngine control module
What each part of P0571 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| 71 | The exact fault in that area. |
What to do next
- Note P0571 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0571
What does P0571 mean?
P0571 means "Brake Switch A Circuit". Brake switch A is the brake light switch or its signal to the engine module. It is a generic code, so it means the same on every make.
Is it safe to drive with P0571?
P0571 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P0571 fail an emissions test?
P0571 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P0571 to fix?
Difficulty: easy. A typical repair takes 0.3 to 1 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0571 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.