C004B: Brake Fluid Level Sensor/Switch Circuit/Open
Standardized SAE J2012 code · C00xx codes
Safety-critical system. Faults in airbags, brakes, steering or high-voltage components can put people at risk. Follow the manufacturer's service information and safety procedures, or have the vehicle checked by a qualified workshop.
What does C004B mean?
Open circuit on brake fluid level sensor or switch.
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Common causes
- High Wiring open
- Low Pin pushed back out of connector body
- Low Cracked solder joint inside the module or sensor
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of C004B on the same make and model first.
C004B in the community
Ask about C004BNo one has posted about C004B yet
Share your vehicle, the tool you used and what you tested — the first thread helps everyone who searches for this code.
Describe your C004B problem