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 getting a steady signal from the sensor that measures how fast the left rear wheel is spinning.
The wheel speed sensor sends information about the wheel's speed to the car's computer. If the signal is not steady, it can cause issues with systems like ABS.
The C0663 code indicates that the left rear wheel speed sensor, designated as 'Sensor B', is sending an intermittent or erratic signal. This can affect the vehicle's anti-lock braking system (ABS) and traction control system, as these systems rely on accurate wheel speed data to function correctly.
• ABS warning light on
• Traction control light on
• Inconsistent braking performance
• Faulty wheel speed sensor
• Damaged wiring or connector
• Debris or dirt on the sensor or tone ring
ABS: Anti-lock Braking System
Sensor: A device that detects or measures a physical property and records, indicates, or otherwise responds to it.
• Inspect the left rear wheel speed sensor and wiring for damage.
• Check for debris or dirt on the sensor or tone ring.
• Use a multimeter to test the sensor's electrical output.
• Clean the sensor and tone ring.
• Repair or replace damaged wiring or connectors.
• Replace the faulty wheel speed sensor.
• OBD-II scanner
• Multimeter
• Basic hand tools
$100 - $300
Moderate
• Chevrolet Silverado
• GMC Sierra
• Cadillac Escalade
• Regularly inspect wheel speed sensors for damage.
• Keep the sensor area clean from debris.
• Ensure wiring and connectors are secure.
Sensor Issue
• Avoid driving in harsh conditions until repaired.
• Have the vehicle inspected by a professional if unsure.
• Monitor for any changes in braking performance.
Check with the vehicle manufacturer for specific warranty coverage related to sensor issues.
Wheel speed sensor issues have been common in vehicles with advanced braking systems due to their reliance on precise data.
Moderate – While the vehicle may still be drivable, braking performance can be compromised.
Driving with a faulty wheel speed sensor can affect braking performance and may be unsafe. Address the issue promptly.
• Vehicle on a level surface
• Engine off and wheels safely elevated
The left rear wheel speed sensor is located near the wheel hub of the left rear wheel.
Q: Can I drive with a C0663 code?
A: It's possible to drive, but it's not recommended as it can affect braking performance.
Q: How can I prevent this issue?
A: Regular maintenance and keeping the sensor area clean can help prevent this issue.
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.
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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.
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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.