OBD Guide

C128E

ABS Master Cylinder Pressure Sensor Raw Offset Error

C128E is an OBD-II diagnostic trouble code meaning: ABS Master Cylinder Pressure Sensor Raw Offset Error. Common causes: master cylinder pressure sensor malfunction, problems with the wiring harness to the sensor. Estimated repair cost: $56–167.

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

Symptoms

  • The ABS warning light on the dashboard comes on
  • Disabling the ABS system
  • Incorrect operation of the ESP/TCS system (if installed)
  • Unusual behavior of the brake pedal

Causes

  • Master cylinder pressure sensor malfunction
  • Problems with the wiring harness to the sensor
  • Corrosion or poor contact in connectors
  • Low brake fluid level
  • Air entering the hydraulic system
  • ABS module malfunction

How to Fix

  1. Check the level and condition of the brake fluid
  2. Visually inspect the pressure sensor and its connection
  3. Check the integrity and resistance of the wiring harness
  4. Using a diagnostic scanner, check the actual sensor values
  5. If necessary, replace the pressure sensor
  6. Bleed the brake system (if signs of air ingress are detected)

Related codes

FAQ

What does the C128E code mean?

C128E is an OBD-II diagnostic trouble code that indicates: ABS Master Cylinder Pressure Sensor Raw Offset Error

What causes a C128E error code?

The most common causes of C128E include: Master cylinder pressure sensor malfunction; Problems with the wiring harness to the sensor; Corrosion or poor contact in connectors; Low brake fluid level.

How do I fix a C128E diagnostic trouble code?

To fix C128E: Check the level and condition of the brake fluid. Visually inspect the pressure sensor and its connection. Check the integrity and resistance of the wiring harness. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C128E?

Limited driving only, diagnose soon

How much does it cost to fix C128E?

The estimated repair cost for C128E is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat