OBD Guide

C1027

Left Rear Wheel Speed Sensor Signal Erratic Performance

C1027 is an OBD-II diagnostic trouble code meaning: Left Rear Wheel Speed Sensor Signal Erratic Performance. Common causes: damaged wheel speed sensor, sensor contamination. Estimated repair cost: $33–111.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$33–111 (est.)

Symptoms

  • ABS/ESP indicator is on
  • Incorrect ABS operation
  • Disabling the ESP system
  • Problems with cruise control

Causes

  • Damaged wheel speed sensor
  • Sensor contamination
  • Broken or damaged wiring harness
  • Poor contact in the sensor connector
  • Malfunction of the sensor ring (benchmark)
  • Problems with the ABS/ESP control unit

How to Fix

  1. Visually check the sensor and wiring harness for damage
  2. Clean the sensor from dirt
  3. Check the sensor resistance (compare with reference values)
  4. Check the integrity of the wiring harness and contacts in the connector
  5. Check the condition of the sensor ring (benchmark)
  6. If necessary, replace the wheel speed sensor
  7. Clear the error and check if it returns

Related codes

FAQ

What does the C1027 code mean?

C1027 is an OBD-II diagnostic trouble code that indicates: Left Rear Wheel Speed Sensor Signal Erratic Performance

What causes a C1027 error code?

The most common causes of C1027 include: Damaged wheel speed sensor; Sensor contamination; Broken or damaged wiring harness; Poor contact in the sensor connector.

How do I fix a C1027 diagnostic trouble code?

To fix C1027: Visually check the sensor and wiring harness for damage. Clean the sensor from dirt. Check the sensor resistance (compare with reference values). For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C1027?

Limited driving only, diagnose soon

How much does it cost to fix C1027?

The estimated repair cost for C1027 is $33–111. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat