C004B
Brake Fluid Level Sensor/Switch Circuit/Open
Open circuit on brake fluid level sensor or switch.
Open circuit on brake fluid level sensor or switch.
Common causes
- high
Wiring open
One of the most commonly reported causes for this code — check this first.
Typical part cost: $30-220
- low
Pin pushed back out of connector body
Less common, but worth ruling out after the more likely causes.
Typical part cost: $30-220
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does C004B mean?
C004B means "Brake Fluid Level Sensor/Switch Circuit/Open". It is a generic OBD-II code that points to a fault in the chassis.
What are the most common causes of C004B?
wiring open; pin pushed back out of connector body; cracked solder joint inside the module or sensor — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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