C05D0

Brake Master Cylinder Piston Position Sensor A/B Correlation

Severity

🔴 High

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$167–444 (est.)

Symptoms

The brake system fault indicator is on
Reduced ABS/ESP performance
Unusual behavior of the brake pedal
Loss of emergency braking function

Causes

Piston position sensor A or B faulty
Damage to the sensor wiring harness
Mechanical problems in the master cylinder
Corrosion of sensor contacts
Problems with the brake system control unit

How to Fix

Diagnostics of the brake system with a scanner
Checking resistance and sensor signals
Inspect the wiring harness for damage
Checking the mechanical condition of the master cylinder
Replacing faulty components
Programming/adaptation of a new block if necessary

Related codes

C05D1 C05D2 C0035 C0040