What it means
The brake booster temperature sensor C signal is outside its expected range or does not match expected behavior.
At a glance
- Usually lights the ABS or stability-control warning light
How it works
Brake booster temperature sensor C reports temperature to the brake control module, which checks whether the reading behaves within an expected range. This code sets when the signal is implausible or outside that range, even if the circuit is not simply open or shorted. A drifting sensor element or loose mounting can make its reading inaccurate or poorly responsive.
Common causes
Most likely first.
- Sensor reading drifted
- Sensor element aged beyond calibration window
- Sensor mounting loose - signal damping
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
How to diagnose it
- Review brake-module freeze-frame and live data to see whether sensor C's reading is implausible, stuck, or slow to change.
- Inspect sensor C and its mounting for looseness or disturbance that could affect how it senses booster temperature.
- Check the connector and wiring for corrosion, damage, or high resistance that could distort the signal.
- Compare sensor C's reading with other available temperature information under comparable conditions, using the manufacturer's diagnostic guidance.
- Test sensor C across its operating range and verify its mounting and circuit against the manufacturer's specification.
Common fixes
- Secure sensor C if its mounting is loose.
- Repair corroded terminals or wiring with excessive resistance.
- Replace sensor C if its reading remains inaccurate after the circuit and mounting are checked.
- Carry out any required calibration or setup using the manufacturer's procedure.
Can I keep driving?
ABS or stability control may be limited, and brake assist may be reduced. If the brakes feel normal, drive cautiously and allow extra stopping distance; stop safely if braking changes.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.