C05BF

What it means

Brake Booster Motor B Position Sensor Supply Circuit Range/Performance: the signal is implausible or outside the valid range. The electric brake booster generates the braking assist; a motor or sensor fault can reduce or disable power-assisted braking. Safety-relevant.

Is it safe to drive?

This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.

Most likely causes

• Connector with high resistance

  high

  One of the most commonly reported causes for this code — check this first.

• Sensor element aged beyond calibration window

  low

  Less common, but worth ruling out after the more likely causes.

• Sensor mounting loose - signal damping

  low

  Less common, but worth ruling out after the more likely causes.

Related help

• Full C05BF diagnosis, causes & costs
• How to read check engine light codes
• Is it safe to drive with the light on?