OBD Guide

C0666

Right Rear Wheel Speed Sensor B Circuit/Open

C0666 is an OBD-II diagnostic trouble code meaning: Right Rear Wheel Speed Sensor B Circuit/Open. Common causes: broken or damaged wiring harness to the sensor, poor contact in the sensor connector. Estimated repair cost: $33–111.

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

Symptoms

  • The ABS, ESP or stabilization system warning light is on
  • Disabling the ABS or ESP system
  • Incorrect operation of cruise control
  • Errors in related systems

Causes

  • Broken or damaged wiring harness to the sensor
  • Poor contact in the sensor connector
  • Malfunction of the wheel speed sensor itself
  • Damage to the gear rotor (comb) on the hub
  • Problems with the ABS ECU

How to Fix

  1. Check the integrity of the wiring harness to the sensor
  2. Inspect connectors for oxidation or damage
  3. Check sensor resistance (must meet specification)
  4. Clean the sensor and gear rotor from dirt
  5. Replacing a faulty speed sensor
  6. Check the operation of the system after repair

Related codes

Error C0666 by Vehicle Brand

FAQ

What does the C0666 code mean?

C0666 is an OBD-II diagnostic trouble code that indicates: Right Rear Wheel Speed Sensor B Circuit/Open

What causes a C0666 error code?

The most common causes of C0666 include: Broken or damaged wiring harness to the sensor; Poor contact in the sensor connector; Malfunction of the wheel speed sensor itself; Damage to the gear rotor (comb) on the hub.

How do I fix a C0666 diagnostic trouble code?

To fix C0666: Check the integrity of the wiring harness to the sensor. Inspect connectors for oxidation or damage. Check sensor resistance (must meet specification). For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C0666?

Limited driving only, diagnose soon

How much does it cost to fix C0666?

The estimated repair cost for C0666 is $33–111. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat