OBD Guide

C1421

Open or Short in Master Cylinder Pressure Sensor

C1421 is an OBD-II diagnostic trouble code meaning: Open or Short in Master Cylinder Pressure Sensor. Common causes: broken or damaged sensor wiring harness, short circuit in the circuit. Estimated repair cost: $56–167.

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

Symptoms

  • ABS/ESP indicator is on
  • Disabling the stabilization system
  • Incorrect ABS operation
  • Errors in other brake-related systems

Causes

  • Broken or damaged sensor wiring harness
  • Short circuit in the circuit
  • Oxidation of contacts
  • Malfunction of the pressure sensor itself
  • Problems with the ABS/ESP control unit

How to Fix

  1. Check the integrity of the wiring harness to the sensor
  2. Check contacts for corrosion
  3. Measure sensor resistance
  4. Check the reference voltage and signal from the sensor
  5. If necessary, replace the sensor or repair the harness

Related codes

FAQ

What does the C1421 code mean?

C1421 is an OBD-II diagnostic trouble code that indicates: Open or Short in Master Cylinder Pressure Sensor

What causes a C1421 error code?

The most common causes of C1421 include: Broken or damaged sensor wiring harness; Short circuit in the circuit; Oxidation of contacts; Malfunction of the pressure sensor itself.

How do I fix a C1421 diagnostic trouble code?

To fix C1421: Check the integrity of the wiring harness to the sensor. Check contacts for corrosion. Measure sensor resistance. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C1421?

Limited driving only, diagnose soon

How much does it cost to fix C1421?

The estimated repair cost for C1421 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat