OBD Guide

C0661

Left Rear Wheel Speed Sensor B Circuit Low

C0661 is an OBD-II diagnostic trouble code meaning: Left Rear Wheel Speed Sensor B Circuit Low. Common causes: wheel speed sensor malfunction, open or shorted wiring harness. 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
  • Disabling the anti-lock braking system
  • Incorrect operation of cruise control
  • Errors in other systems

Causes

  • Wheel speed sensor malfunction
  • Open or shorted wiring harness
  • Problems with the sensor connector
  • ABS module malfunction

How to Fix

  1. Check the integrity of the wiring harness and sensor connector
  2. Measure the resistance of the wheel speed sensor
  3. Check the sensor signal using an oscilloscope
  4. Replace the wheel speed sensor if necessary
  5. Check and clean magnetic ring (if applicable)
  6. Check the power and ground of the sensor circuit

Related codes

Error C0661 by Vehicle Brand

FAQ

What does the C0661 code mean?

C0661 is an OBD-II diagnostic trouble code that indicates: Left Rear Wheel Speed Sensor B Circuit Low

What causes a C0661 error code?

The most common causes of C0661 include: Wheel speed sensor malfunction; Open or shorted wiring harness; Problems with the sensor connector; ABS module malfunction.

How do I fix a C0661 diagnostic trouble code?

To fix C0661: Check the integrity of the wiring harness and sensor connector. Measure the resistance of the wheel speed sensor. Check the sensor signal using an oscilloscope. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C0661?

Limited driving only, diagnose soon

How much does it cost to fix C0661?

The estimated repair cost for C0661 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat