C0644

Brake Pressure Sensor K Range/Performance

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

Symptoms

The brake system fault indicator is on
Reduced braking performance
Unstable operation of ABS or ESP
Unusual behavior of the brake pedal

Causes

Brake pressure sensor malfunction
Open or short circuit in wiring harness
Poor contact in the sensor connector
Problems with the brake system (leaks, air in the system)
Brake ECU malfunction

How to Fix

Check the brake pressure sensor for damage
Check the wiring harness and connectors for breaks and corrosion.
Check the pressure in the brake system
Replace brake pressure sensor if necessary
Clear error codes and check if C0644 returns

Related codes

C0645 C0646 C0040