OBD-II Fault Code

C1172: Park Brake Switch # 1 Applied Circuit Failure

Meaning, symptoms, likely causes, diagnostic checks and repair guidance for C1172.

System family

Chassis

Manufacturer-specific

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 C1172 usually means

Park Brake Switch # 1 Applied Circuit Failure.

Common symptoms

ABS/traction/steering/suspension warning lamp or abnormal chassis behaviour; 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

Inspect wheel/brake/suspension area, connectors, sensor wiring and module power/ground; 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 safely at low speed first, then rescan

Note: Brake/ABS repairs affect safety; use qualified repair support when unsure; Manufacturer-specific: confirm definition and test steps in the vehicle service manual. A DTC identifies a circuit or system condition, not always the failed part.