Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer is having trouble understanding the speed of the left back wheel. It's like when you can't hear your friend clearly because of a bad phone connection.
The vehicle's ABS (Anti-lock Braking System) control module has detected a correlation issue with the left rear wheel speed sensor. This means the sensor's readings are not matching expected values.
The C0511 code indicates a discrepancy between the actual wheel speed and the expected wheel speed as determined by the ABS control module. The sensor may not be sending consistent signals, or there may be an issue with the wiring or connections.
• ABS warning light illuminated
• Inconsistent braking performance
• Traction control system may be disabled
• Faulty left rear wheel speed sensor
• Damaged or corroded wiring or connectors
• Faulty ABS control module
ABS: Anti-lock Braking System
OBD-II: On-Board Diagnostics II
• Check for any visible damage to the wheel speed sensor or wiring.
• Use a multimeter to test the sensor's resistance and output.
• Inspect the ABS control module for faults.
• Replace the faulty wheel speed sensor.
• Repair or replace damaged wiring or connectors.
• Replace the ABS control module if necessary.
• OBD-II scanner
• Multimeter
• Socket set
$100 - $300
Moderate
• Chevrolet Silverado
• GMC Sierra
• Cadillac Escalade
• Regularly inspect wheel speed sensors and wiring.
• Keep the wheel area clean from debris.
• Ensure proper maintenance of the ABS system.
Sensor Issue
• Avoid driving in conditions where ABS is crucial until repaired.
• Regularly check for warning lights on the dashboard.
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 can still be driven, braking performance may be compromised.
Driving with a malfunctioning ABS can increase the risk of accidents, especially in wet or slippery conditions.
• Vehicle at operating temperature
• Clear and dry road conditions
The left rear wheel speed sensor is located near the wheel hub of the left rear wheel.
Q: What does a wheel speed sensor do?
A: A wheel speed sensor measures the speed of the wheel and sends this information to the ABS control module.
Q: Can I drive with a C0511 code?
A: It's possible to drive, but it's not recommended as braking performance may be affected.
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.
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