C05B5Brake Booster Temperature Sensor C Circuit/Open
- Generic OBD-II code · Chassis
- How the car detects it
- C05B5 is reserved for an interrupted circuit of booster temperature sensor C. No manufacturer documents it publicly; Mitsubishi, the one maker naming sensor C codes, reports problems with this channel only as C05B3 or C05B4. Boosters typically carry several NTC thermistors: Hitachi Astemo places one on the motor and one in the controller near the motor drive stage and caps motor current when either runs hot. If a thermistor or its lead breaks, the divider sits at one rail; a supplier overview cautions that such a rail reading alone cannot separate every wiring, reference or converter fault. Microchip adds that a board or module NTC follows case temperature, not the transistor junction. As the sensor is mostly internal, repair normally means a new booster unit.
- What you may notice
- Brake or brake system warning lamp on
- Booster may restrict assist as a precaution, depending on design
- Likely causes
- LikelyCracked thermistor body or broken lead inside the booster
- PossibleFractured solder joint on the control board from vibration or heat cycles
- RareOpen wire or pin where the sensor is wired externally
- Repair
- Hard · Usually a job for a workshop.Typical cost: €150 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.