OBD-II Fault Code

P0571: Cruise Control/Brake Switch A Circuit Malfunction

Meaning, symptoms, likely causes, diagnostic checks and repair guidance for P0571.

System family

Powertrain

Generic/SAE

Repair category

ABS / brake system

Use this category to narrow your checks before replacing parts.

Severity

High

Severity is a general guide. Confirm with scan-tool data and vehicle symptoms.

What P0571 usually means

Cruise Control/Brake Switch A Circuit Malfunction.

Common symptoms

Check Engine light; Poor drivability or reduced fuel economy depending on fault; ABS/traction light, ABS disabled, possible speedometer or stability-control issues

Likely causes

Dirty/damaged wheel speed sensor; Damaged tone ring/bearing; Wiring fault; ABS pump/module issue

Diagnostic checks

Scan all modules and record freeze-frame data before clearing codes; Check battery voltage and related fuses; Inspect wheel speed sensor wiring and tone ring; Compare live wheel speed data while spinning wheels safely

Repair guidance

Repair sensor wiring or replace failed sensor/bearing/tone ring; Diagnose pump/module only after sensor circuits pass

Verification after repair

Clear code, road-test through the same drive condition, then rescan

Note: Brake/ABS repairs affect safety; use qualified repair support when unsure. A DTC identifies a circuit or system condition, not always the failed part.