OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Chassis generic / SAE

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.

SystemChassis
Typegeneric / SAE
GroupC0
Range / number5 / B5

Possible causes

  • Signal wire open high
  • Pin pushed back out of connector body low
  • Cracked solder joint inside the module or sensor low

Symptoms

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

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 150–1200 €
  • Estimated time: 1–4 h
  • Component: brake booster temp sensor c
  • MIL / check engine light

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication