OBD Guide

C05B4

Brake Booster Temperature Sensor C Circuit High

C05B4 is an OBD-II diagnostic trouble code meaning: Brake Booster Temperature Sensor C Circuit High. Common causes: brake booster temperature sensor malfunction, short circuit in the sensor circuit. Estimated repair cost: $56–167.

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

Symptoms

  • Check Engine Light Is On
  • Reduced braking performance
  • Disabling Brake Assist

Causes

  • Brake booster temperature sensor malfunction
  • Short circuit in the sensor circuit
  • Broken or damaged wiring
  • Problems with sensor connectors
  • Malfunction of the brake system control unit

How to Fix

  1. Check the integrity of the sensor wiring and connectors
  2. Measure the sensor resistance (compare with nominal values)
  3. Check the voltage in the sensor circuit
  4. If necessary, replace the brake booster temperature sensor
  5. Reset the error and check if it returns

Related codes

Error C05B4 by Vehicle Brand

FAQ

What does the C05B4 code mean?

C05B4 is an OBD-II diagnostic trouble code that indicates: Brake Booster Temperature Sensor C Circuit High

What causes a C05B4 error code?

The most common causes of C05B4 include: Brake booster temperature sensor malfunction; Short circuit in the sensor circuit; Broken or damaged wiring; Problems with sensor connectors.

How do I fix a C05B4 diagnostic trouble code?

To fix C05B4: Check the integrity of the sensor wiring and connectors. Measure the sensor resistance (compare with nominal values). Check the voltage in the sensor circuit. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C05B4?

Limited driving only, diagnose soon

How much does it cost to fix C05B4?

The estimated repair cost for C05B4 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat