OBD-II code · Chassis

C057D Brake Booster Temperature Sensor Circuit B Intermittent/Erratic

Intermittent signal from brake booster temp sensor B. 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 C057D?

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

Common causes

  • Most likelyConnector loose
  • Less likelyConnector with intermittent contact under vibration
  • Less likelyHarness routed against vibrating component

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
0.5–3 h
Emissions test
Usually unaffected
After the fix
A drive cycle is needed before the light stays off
Parts involved
Brake Booster Temp Sensor B

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