C05B8

Brake Booster Motor A Position Sensor Supply Circuit/Open

Severity

🔴 High

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

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

C05B9 C05BA C05BB C05BC C05BD