OBD Guide

C0027

Left Front Wheel Speed Sensor Signal Erratic

C0027 is an OBD-II diagnostic trouble code meaning: Left Front Wheel Speed Sensor Signal Erratic. Common causes: wheel speed sensor malfunction, wiring harness damage. 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
  • Uneven operation of ABS
  • Incorrect speedometer readings (in some models)
  • Loss of ESP functions

Causes

  • Wheel speed sensor malfunction
  • Wiring harness damage
  • Contamination or damage to the gear ring (rotor)
  • Lost contact in the connector
  • Problems with the ABS/ESP module

How to Fix

  1. Visually inspect the sensor and wiring harness for damage
  2. Checking the sensor resistance (compare with factory specifications)
  3. Cleaning the sensor and gear ring from dirt
  4. Checking continuity with an oscilloscope or scanner
  5. If necessary, replace the sensor or repair the wiring harness

Related codes

Error C0027 by Vehicle Brand

FAQ

What does the C0027 code mean?

C0027 is an OBD-II diagnostic trouble code that indicates: Left Front Wheel Speed Sensor Signal Erratic

What causes a C0027 error code?

The most common causes of C0027 include: Wheel speed sensor malfunction; Wiring harness damage; Contamination or damage to the gear ring (rotor); Lost contact in the connector.

How do I fix a C0027 diagnostic trouble code?

To fix C0027: Visually inspect the sensor and wiring harness for damage. Checking the sensor resistance (compare with factory specifications). Cleaning the sensor and gear ring from dirt. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C0027?

Limited driving only, diagnose soon

How much does it cost to fix C0027?

The estimated repair cost for C0027 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat