OBD-II code · Chassis

C05B5 Brake Booster Temperature Sensor C Circuit/Open

Open circuit on brake booster temperature sensor C. Boost control tracks commanded vs. actual manifold pressure; persistent deviation means wastegate, vanes, hose or actuator are not delivering the requested pressure.

Is it safe to drive with C05B5?

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

Common causes

  • Most likelySignal wire open
  • Less likelyPin pushed back out of connector body
  • Less likelyCracked solder joint inside the module or sensor

Symptoms

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

Repair at a glance

Difficulty
Medium
DIY friendly
Best left to a mechanic
Typical labour
1–4 h
Emissions test
Usually unaffected
Parts involved
Brake Booster Temp Sensor C

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