OBD-II code · Chassis
C05B7 Brake Booster Temperature Sensor C Circuit Intermittent/Erratic
Intermittent signal from 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 C05B7?
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 C
Related codes
- P25C8Brake Booster Temperature Sensor A Circuit Intermittent/Erratic
- C05B4Brake Booster Temperature Sensor C Circuit High
- C05B5Brake Booster Temperature Sensor C Circuit/Open
- C05B6Brake Booster Temperature Sensor C Circuit Range/Performance
- C05B8Brake Booster Motor A Position Sensor Supply Circuit/Open
- C05B9Brake Booster Motor A Position Sensor Supply Circuit Low
- C05BABrake Booster Motor A Position Sensor Supply Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.