OBD Guide

C05BF

Brake Booster Motor B Position Sensor Supply Circuit Range/Performance

C05BF is an OBD-II diagnostic trouble code meaning: Brake Booster Motor B Position Sensor Supply Circuit Range/Performance. Common causes: brake booster motor position sensor fault b, open or short circuit in wiring harness. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Increased brake pedal force
  • The brake system fault indicator is on
  • Uneven operation of the brake booster
  • Reduced braking performance

Causes

  • Brake booster motor position sensor fault B
  • Open or short circuit in wiring harness
  • Poor contact in connectors
  • Contact corrosion
  • Low voltage in the on-board network
  • Malfunction of the brake system control unit

How to Fix

  1. Check the voltage in the on-board network
  2. Inspect the wiring harness for damage
  3. Check the contacts in the sensor and control unit connectors
  4. Test brake booster motor position sensor B
  5. If necessary, replace the sensor or wiring harness
  6. Check and, if necessary, replace the brake system control unit

Related codes

Error C05BF by Vehicle Brand

FAQ

What does the C05BF code mean?

C05BF is an OBD-II diagnostic trouble code that indicates: Brake Booster Motor B Position Sensor Supply Circuit Range/Performance

What causes a C05BF error code?

The most common causes of C05BF include: Brake booster motor position sensor fault B; Open or short circuit in wiring harness; Poor contact in connectors; Contact corrosion.

How do I fix a C05BF diagnostic trouble code?

To fix C05BF: Check the voltage in the on-board network. Inspect the wiring harness for damage. Check the contacts in the sensor and control unit connectors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C05BF?

Limited driving only, diagnose soon

How much does it cost to fix C05BF?

The estimated repair cost for C05BF is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat