Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer has detected a problem with the sensor that tells where the brake pedal is. It's like when a video game controller doesn't know if you're pressing a button or not.
The brake master cylinder piston position sensor monitors the position of the brake pedal. If the sensor's voltage is lower than expected, this code is triggered.
The C05CB code indicates that the voltage output from the brake master cylinder piston position sensor is below the threshold set by the manufacturer. This sensor is crucial for the electronic brake control system to function properly, as it provides feedback on the position of the brake pedal.
• ABS warning light on
• Brake system warning light on
• Reduced braking performance
• Faulty brake master cylinder piston position sensor
• Wiring issues such as a short circuit or open circuit
• Faulty electronic brake control module
Brake Master Cylinder: A component that converts the force from the brake pedal into hydraulic pressure to apply the brakes.
OBD-II: On-Board Diagnostics, a standardized system in vehicles for self-diagnosing and reporting.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the brake master cylinder piston position sensor for proper voltage output.
• Replace the brake master cylinder piston position sensor if faulty.
• Repair or replace damaged wiring or connectors.
• Replace the electronic brake control module if necessary.
• OBD-II scanner
• Multimeter
• Wrench set
$150 - $400
Moderate
• Chevrolet Silverado
• GMC Sierra
• Cadillac Escalade
• Regularly inspect brake system components.
• Keep electrical connections clean and secure.
• Follow manufacturer-recommended maintenance schedules.
Sensor Issue
• Do not ignore the ABS warning light.
• Have the vehicle inspected by a professional mechanic.
Check your vehicle's warranty booklet for coverage on brake system components.
This code has been reported in vehicles with electronic brake control systems, particularly in models with high mileage.
High – This issue can affect braking performance, which is critical for vehicle safety.
Driving with impaired brakes can lead to accidents. Address this issue promptly to ensure safety.
• Vehicle ignition on
• Brake pedal pressed
The brake master cylinder piston position sensor is typically located near the brake pedal assembly.
Q: Can I drive with the C05CB code?
A: It's not recommended to drive with this code active, as it can affect your braking system's performance.
Q: How do I reset the ABS warning light?
A: Fix the underlying issue first, then use an OBD-II scanner to clear the code and reset the light.
Pro · Four-system diagnostics
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Chassis and ABS faults usually need a scanner that can read brake-system data directly.
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