C05B8
Brake Booster Motor A Position Sensor Supply Circuit/Open
C05B8 is an OBD-II diagnostic trouble code meaning: Brake Booster Motor A Position Sensor Supply Circuit/Open. Common causes: open circuit in the sensor power wiring harness, short circuit in power supply. Estimated repair cost: $56–167.
Symptoms
- Pressing the brake pedal hard
- Reduced braking performance
- ESP/ABS warning light comes on
- Loss of brake booster assistance
- Unstable operation of the brake system
Causes
- Open circuit in the sensor power wiring harness
- Short circuit in power supply
- Amplifier bridge position sensor malfunction
- Poor contact in connectors
- Problems with the brake system control unit
- Contact corrosion
- Mechanical damage to wiring
How to Fix
- Visually inspect the wiring harness for damage
- Checking the integrity of the sensor power supply circuit
- Diagnostics of resistance and voltage in a circuit
- Checking the contacts in the sensor and control unit connectors
- Replacing the position sensor if necessary
- Repair or replace damaged wiring
- Resetting fault codes after repair
Related codes
Error C05B8 by Vehicle Brand
FAQ
What does the C05B8 code mean?
C05B8 is an OBD-II diagnostic trouble code that indicates: Brake Booster Motor A Position Sensor Supply Circuit/Open
What causes a C05B8 error code?
The most common causes of C05B8 include: Open circuit in the sensor power wiring harness; Short circuit in power supply; Amplifier bridge position sensor malfunction; Poor contact in connectors.
How do I fix a C05B8 diagnostic trouble code?
To fix C05B8: Visually inspect the wiring harness for damage. Checking the integrity of the sensor power supply circuit. Diagnostics of resistance and voltage in a circuit. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with C05B8?
Limited driving only, diagnose soon
How much does it cost to fix C05B8?
The estimated repair cost for C05B8 is $56–167. Actual cost depends on your vehicle, location, and labor rates.
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