OBD Guide

C0203

Master Cylinder Pressure Sensor

C0203 is an OBD-II diagnostic trouble code meaning: Master Cylinder Pressure Sensor. Common causes: pressure sensor malfunction, open or shorted wiring harness. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$56–167 (est.)

Symptoms

  • ABS/ESP indicator is on
  • Reduced braking performance
  • Incorrect operation of the stabilization system

Causes

  • Pressure sensor malfunction
  • Open or shorted wiring harness
  • Poor contact in the sensor connector
  • Malfunction of the ABS/ESP control unit

How to Fix

  1. Check the pressure sensor using an OBD-II scanner
  2. Check the integrity of the wiring harness and contacts
  3. Replace sensor if necessary
  4. Check ABS/ESP control unit

Related codes

Error C0203 by Vehicle Brand

FAQ

What does the C0203 code mean?

C0203 is an OBD-II diagnostic trouble code that indicates: Master Cylinder Pressure Sensor

What causes a C0203 error code?

The most common causes of C0203 include: Pressure sensor malfunction; Open or shorted wiring harness; Poor contact in the sensor connector; Malfunction of the ABS/ESP control unit.

How do I fix a C0203 diagnostic trouble code?

To fix C0203: Check the pressure sensor using an OBD-II scanner. Check the integrity of the wiring harness and contacts. Replace sensor if necessary. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C0203?

Do not drive — repair immediately

How much does it cost to fix C0203?

The estimated repair cost for C0203 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat