OBD Guide

U120C

Lost Brake Booster Signal

U120C is an OBD-II diagnostic trouble code meaning: Lost Brake Booster Signal. Common causes: open or short circuit in the brake booster sensor circuit, brake booster sensor malfunction. Estimated repair cost: $33–167.

Severity
🔴 High
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$33–167 (est.)

Symptoms

  • Increased brake pedal force
  • Check Engine Light Is On
  • Reduced braking performance
  • There may be other errors related to the brake system

Causes

  • Open or short circuit in the brake booster sensor circuit
  • Brake booster sensor malfunction
  • Problems with the brake control module
  • Poor contact in connectors
  • Wiring harness damage

How to Fix

  1. Check the continuity of the brake booster sensor circuit
  2. Check the condition of connectors and contacts
  3. Test the brake booster sensor
  4. Check the brake control module
  5. If necessary, replace the sensor or repair the wiring

Related codes

FAQ

What does the U120C code mean?

U120C is an OBD-II diagnostic trouble code that indicates: Lost Brake Booster Signal

What causes a U120C error code?

The most common causes of U120C include: Open or short circuit in the brake booster sensor circuit; Brake booster sensor malfunction; Problems with the brake control module; Poor contact in connectors.

How do I fix a U120C diagnostic trouble code?

To fix U120C: Check the continuity of the brake booster sensor circuit. Check the condition of connectors and contacts. Test the brake booster sensor. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U120C?

Limited driving only, diagnose soon

How much does it cost to fix U120C?

The estimated repair cost for U120C is $33–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat