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ElectricalSeverity Medium: diagnose soon

P0571Brake Switch "A" Circuit

What it means

The ECU sees a fault in the brake pedal switch signal. Cruise control and some start functions depend on it.

Symptoms

  • Cruise control not working
  • Brake lights on all the time or not working
  • Can't move out of Park on some automatics

Common causes

  • Faulty or misadjusted brake light switch
  • Blown brake light fuse
  • Wiring fault

What to check first

  1. Check the brake lights
  2. Watch both brake switch signals in live data
  3. Adjust or replace the switch
Can I drive with P0571? Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.

Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.

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P0571: questions and answers

What does P0571 mean?

P0571: Brake Switch "A" Circuit. The ECU sees a fault in the brake pedal switch signal. Cruise control and some start functions depend on it.

What are the symptoms of P0571?

Cruise control not working. Brake lights on all the time or not working. Can't move out of Park on some automatics.

What causes P0571?

Faulty or misadjusted brake light switch. Blown brake light fuse. Wiring fault.

How do you diagnose P0571?

1. Check the brake lights 2. Watch both brake switch signals in live data 3. Adjust or replace the switch

Can I drive with P0571?

Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.