Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's computer is having trouble understanding the signals from the left back wheel's speed sensor. It's like trying to read a book with missing pages.
The vehicle's control module is detecting inconsistent or unexpected signals from the left rear wheel speed sensor, which may affect vehicle stability control systems.
The C0664 code is triggered when the Electronic Brake Control Module (EBCM) detects a correlation issue with the left rear wheel speed sensor B. This sensor is responsible for monitoring the rotational speed of the wheel and sending this data to the vehicle's control systems. A correlation error indicates that the data from the sensor does not match expected values, possibly due to a malfunction or misalignment.
• ABS warning light on
• Traction control system malfunction
• Unusual braking behavior
• Vehicle stability issues
• Faulty left rear wheel speed sensor
• Damaged or corroded wiring or connectors
• Misaligned sensor or wheel hub
• Faulty EBCM
EBCM: Electronic Brake Control Module
ABS: Anti-lock Braking System
• Inspect the left rear wheel speed sensor and wiring for damage.
• Check the sensor alignment and mounting.
• Use a scan tool to read sensor data and compare with other wheels.
• Test the EBCM for faults.
• Replace the faulty wheel speed sensor.
• Repair or replace damaged wiring or connectors.
• Realign the sensor or wheel hub.
• Replace the Electronic Brake Control Module if necessary.
• OBD-II scan tool
• Multimeter
• Jack and jack stands
• Basic hand tools
$150 - $400
Moderate
• Chevrolet Silverado
• GMC Sierra
• Cadillac Escalade
• Regularly inspect wheel sensors and wiring.
• Keep wheel hubs clean and free from debris.
• Ensure proper alignment during wheel maintenance.
Sensor Issue
• Avoid driving in extreme conditions until repaired.
• Have the vehicle inspected by a professional mechanic.
• Do not ignore the ABS warning light.
Check with the vehicle manufacturer for warranty coverage on ABS components.
This code has been commonly reported in vehicles with high mileage or those frequently driven in harsh conditions.
Moderate – While the vehicle may still be drivable, braking and stability systems could be compromised.
Driving with a malfunctioning ABS system can be dangerous. Ensure repairs are completed promptly to maintain vehicle safety.
• Vehicle on a level surface
• Engine running
• Use of a scan tool to monitor sensor data
The left rear wheel speed sensor is located near the wheel hub of the left rear tire.
Q: Can I drive with a C0664 code?
A: It's not recommended as it may affect your vehicle's braking and stability systems.
Q: How do I reset the ABS light?
A: Fix the underlying issue first, then use an OBD-II scanner to reset the light.
Pro · Four-system diagnostics
A handheld scanner aimed at engine, transmission, ABS, and airbag diagnostic work.
Chassis and ABS faults usually need a scanner that can read brake-system data directly.
View on Amazon
Universal · Torque wrench
Useful when reassembly torque matters for wheel, suspension, and under-hood fasteners.
Useful when wheel, hub, or suspension hardware needs correct reassembly torque.
View on Amazon
Universal · Drive-on ramps
Helpful for safer access underneath the vehicle during exhaust, EVAP, and underbody inspection work.
Helpful for safer access during underbody inspection work.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.