What it means
The brake booster temperature sensor C signal voltage is above the expected range.
At a glance
- Usually lights the ABS or stability-control warning light
How it works
Brake booster temperature sensor C sends a temperature signal to the brake control module for monitoring the booster system. This code sets when the signal voltage is higher than the module's expected range. A signal short to battery voltage, corroded connector pins, or wiring pinched against a power source can cause the high reading.
Common causes
Most likely first.
- Signal wire shorted to battery
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
How to diagnose it
- Check brake-module freeze-frame and live data to verify that sensor C is reading high and determine whether the fault is present continuously.
- Locate sensor C using vehicle-specific service information and inspect its connector and harness for corrosion, pinching, or contact with a power feed.
- Use the wiring diagram to check whether the sensor C signal circuit is shorted to battery voltage.
- Inspect connector terminals for corrosion or poor contact and verify circuit continuity between the sensor and brake control module.
- If the circuit checks out, test sensor C and the module input according to the manufacturer's specification.
Common fixes
- Repair wiring pinched against a battery-voltage source.
- Clean or repair corroded sensor C connector terminals.
- Repair a signal circuit short to battery voltage.
- Replace sensor C if it fails testing with the wiring verified.
- Repair the module connection only if tests identify it as faulty.
Can I keep driving?
ABS or stability control may be unavailable, and brake assist may be reduced. If braking feels normal, drive cautiously with extra stopping distance; stop safely if 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.