What it means
The brake booster temperature sensor C signal voltage is below the expected range.
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 so it can monitor the booster system. This code sets when the sensor C signal voltage is lower than the module's expected range. A signal wire short to ground, corroded connector pins, or chafed wiring can pull the reading low.
Common causes
Most likely first.
- Signal wire shorted to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
How to diagnose it
- Read the brake module's freeze-frame and live data to confirm the sensor C fault and note whether the signal is consistently low or changes.
- Locate sensor C using vehicle-specific service information, then inspect its connector and harness for corrosion, chafing, or contact with ground.
- Check the sensor C signal circuit for an unintended short to ground, following the manufacturer's wiring diagram and test procedure.
- Inspect connector pins for corrosion or poor contact and check circuit continuity between the sensor and brake control module.
- If the wiring and connections pass, test sensor C and its module input according to the manufacturer's specification.
Common fixes
- Repair chafed insulation on the sensor C signal wire.
- Clean or repair corroded connector terminals and restore a sound connection.
- Repair a signal wire short to ground.
- Replace sensor C if it fails the specified test with the circuit verified.
- Repair the module connection only if testing identifies it as the source.
Can I keep driving?
The code may disable stability or ABS functions, and brake assist may be reduced. Drive only if braking feels normal, leave extra stopping distance, and stop safely if the pedal effort 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.