C05D4

Brake Master Cylinder Piston Position Sensor Calibration Not Learned

Severity

🔴 High

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

Symptoms

ABS or ESP indicator is on
Reduced braking performance
Unusual behavior of the brake pedal (too soft/hard)

Causes

Piston position sensor malfunction
Problems with the master cylinder
Sensor is dirty or damaged
Low brake fluid level
Air in the brake system
Problems with wiring or connectors

How to Fix

Check the brake fluid level
Diagnose the piston position sensor with a scanner
Check the integrity of the wiring and connectors
If necessary, replace the sensor or master cylinder
Bleed the brake system
Calibrate the sensor using diagnostic equipment

Related codes

C05D0 C05D1 C05D2