Diagnostic trouble code P0571 on Audi vehicles — what it means, the common
causes, and how to confirm the real fault before replacing parts.
What does P0571 mean?
P0571 indicates: Brake Switch 'A' Circuit.
This relates to the Vehicle speed / idle / auxiliary inputs system.
Common causes of P0571
signal failure of the brake light switch F (Hall element sensor on tandem master cylinder)
What to check (live data)
brake switch signal state ('brake pressed' / not pressed) on powertrain CAN data bus
Parts often involved in P0571
brake light switch F
tandem master cylinder (Hall element component)
Don't replace parts until the root cause is confirmed — many of these codes are caused by wiring, a connector or an upstream fault, not the part itself.
Get the confirmed root cause for P0571 — on YOUR vehicle
A code is a symptom, not a diagnosis. AutoDX Pro cross-checks several
independent assessments, pinpoints the actual root cause, gives you the
exact tests to confirm it, and shows the parts — only after the cause is
confirmed. Reads your scan-tool photo and decodes your VIN with open
recalls.
P0571 is a diagnostic trouble code: Brake Switch 'A' Circuit.
What are the common causes of P0571 on an Audi?
Common causes include: signal failure of the brake light switch F (Hall element sensor on tandem master cylinder). The exact cause depends on the vehicle — confirm it before replacing parts.
Can I keep driving an Audi with P0571?
It depends on the fault and your symptoms. Some causes are minor, others can damage components or affect safety. Get the root cause confirmed before deciding.
How do I fix P0571 on an Audi?
Confirm the actual root cause with targeted tests first, then replace only the part that's at fault. AutoDX Pro gives you the root cause, the exact tests, and the parts for P0571 on your specific Audi.