OBD-II code · Chassis

C0161 ABS/TCS Brake Switch Circuit

The ABS or traction control module has detected an implausible signal from the brake light switch. The switch tells the module whether the driver is braking and is used to inhibit traction control during braking.

Is it safe to drive with C0161?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyBrake light switch failed or misadjusted
  • PossibleWiring or connector fault

Symptoms

  • ABS warning light on
  • ESC/stability control deactivated
  • Possible reduced brake assist
  • Speedometer may behave erratically

Repair at a glance

Difficulty
Easy
DIY friendly
Often, with basic tools
Typical labour
0.3–1 h
Emissions test
Usually unaffected
Parts involved
Brake Light Switch, ABS Control Module, Tcs Control Module

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.