OBD Guide

C0634

Brake Pressure Sensor A/B Correlation

C0634 is an OBD-II diagnostic trouble code meaning: Brake Pressure Sensor A/B Correlation. Common causes: brake pressure sensor malfunction, problems in the wiring harness or sensor connectors. Estimated repair cost: $56–167.

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

Symptoms

  • ABS/ESP/SRS indicator is on
  • Reduced braking performance
  • Activating the emergency brake system
  • Malfunctions in the stability control system

Causes

  • Brake pressure sensor malfunction
  • Problems in the wiring harness or sensor connectors
  • Low brake fluid level
  • Air in the brake system
  • EBCM control module software error

How to Fix

  1. Checking the level and condition of the brake fluid
  2. Diagnostics of power circuits and signal lines of sensors
  3. Checking the resistance and signals of pressure sensors
  4. Soft reset and calibration of the EBCM
  5. Replacing a faulty pressure sensor or wiring harness
  6. Bleeding the brake system if necessary

Related codes

Error C0634 by Vehicle Brand

FAQ

What does the C0634 code mean?

C0634 is an OBD-II diagnostic trouble code that indicates: Brake Pressure Sensor A/B Correlation

What causes a C0634 error code?

The most common causes of C0634 include: Brake pressure sensor malfunction; Problems in the wiring harness or sensor connectors; Low brake fluid level; Air in the brake system.

How do I fix a C0634 diagnostic trouble code?

To fix C0634: Checking the level and condition of the brake fluid. Diagnostics of power circuits and signal lines of sensors. Checking the resistance and signals of pressure sensors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C0634?

Limited driving only, diagnose soon

How much does it cost to fix C0634?

The estimated repair cost for C0634 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat