OBD Guide

C0078

Tire Diameter

C0078 is an OBD-II diagnostic trouble code meaning: Tire Diameter. Common causes: installing the wrong size wheels, wheel speed sensor malfunction. Estimated repair cost: $33–111.

Severity
⚠️ Medium
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$33–111 (est.)

Symptoms

  • ABS/ESP indicator is on
  • Reduced ABS performance
  • False alarms of the stabilization system

Causes

  • Installing the wrong size wheels
  • Wheel speed sensor malfunction
  • Wiring Harness Problems
  • ABS/ESP unit programming error

How to Fix

  1. Check that the wheel diameter corresponds to the standard
  2. Diagnose wheel speed sensors
  3. Check the integrity of the wiring harness
  4. Reprogram the ABS/ESP unit

Related codes

Error C0078 by Vehicle Brand

FAQ

What does the C0078 code mean?

C0078 is an OBD-II diagnostic trouble code that indicates: Tire Diameter

What causes a C0078 error code?

The most common causes of C0078 include: Installing the wrong size wheels; Wheel speed sensor malfunction; Wiring Harness Problems; ABS/ESP unit programming error.

How do I fix a C0078 diagnostic trouble code?

To fix C0078: Check that the wheel diameter corresponds to the standard. Diagnose wheel speed sensors. Check the integrity of the wiring harness. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C0078?

Do not drive — repair immediately

How much does it cost to fix C0078?

The estimated repair cost for C0078 is $33–111. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat