OBD Guide

C1040

Rear Wheel Speed Comparative Performance

C1040 is an OBD-II diagnostic trouble code meaning: Rear Wheel Speed Comparative Performance. Common causes: wheel speed sensor malfunction, damage to the wiring or sensor connector. Estimated repair cost: $56–167.

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

Symptoms

  • The ABS/ESP indicator on the dashboard lights up
  • Disabling ABS and ESP
  • Unstable behavior of the car when braking

Causes

  • Wheel speed sensor malfunction
  • Damage to the wiring or sensor connector
  • Rear tire pressure difference
  • Damage to drives or wheel bearings
  • Problems with the ABS/ESP control unit

How to Fix

  1. Check the pressure in the rear tires
  2. Visually inspect the speed sensors and their wiring
  3. Check speed sensor readings using a diagnostic scanner
  4. Replace a faulty speed sensor or repair damaged wiring
  5. Test the ABS/ESP system after repair

Related codes

FAQ

What does the C1040 code mean?

C1040 is an OBD-II diagnostic trouble code that indicates: Rear Wheel Speed Comparative Performance

What causes a C1040 error code?

The most common causes of C1040 include: Wheel speed sensor malfunction; Damage to the wiring or sensor connector; Rear tire pressure difference; Damage to drives or wheel bearings.

How do I fix a C1040 diagnostic trouble code?

To fix C1040: Check the pressure in the rear tires. Visually inspect the speed sensors and their wiring. Check speed sensor readings using a diagnostic scanner. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C1040?

Limited driving only, diagnose soon

How much does it cost to fix C1040?

The estimated repair cost for C1040 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat