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 speed of the front left wheel. It's like when you're trying to read a book but the words are jumbled up.
The vehicle's control module is detecting an inconsistency or mismatch in the signals from the left front wheel speed sensor.
The C0505 code is triggered when the ABS (Anti-lock Braking System) module detects a correlation issue between the expected wheel speed and the actual speed reported by the left front wheel speed sensor. This can affect the vehicle's ability to maintain traction and stability.
• ABS warning light on
• Traction control light on
• Inconsistent speedometer readings
• Faulty wheel speed sensor
• Damaged wiring or connectors
• Faulty ABS module
ABS: Anti-lock Braking System
OBD-II: On-Board Diagnostics, Second Generation
• Inspect the left front wheel speed sensor for damage.
• Check the wiring and connectors for any signs of wear or corrosion.
• Use a diagnostic scanner to read ABS module data.
• Replace the faulty wheel speed sensor.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ABS module if necessary.
• OBD-II scanner
• Multimeter
• Socket set
$100 - $300
Moderate
• Chevrolet Silverado
• GMC Sierra
• Cadillac Escalade
• Regularly inspect wheel speed sensors.
• Keep the ABS system clean and free of debris.
• Perform regular maintenance checks.
Sensor Issue
• Avoid driving in harsh conditions until repaired.
• Consult a professional mechanic for diagnosis.
• Do not ignore the ABS warning light.
Check with the vehicle manufacturer for specific warranty coverage on ABS components.
This code has been commonly reported in vehicles with high mileage or those frequently driven in harsh conditions.
Moderate – It's important to address this issue to ensure proper vehicle handling and safety.
Driving with a malfunctioning ABS system can reduce vehicle safety and may be illegal in some regions.
• Vehicle on a flat surface
• Ignition in the 'on' position
The left front wheel speed sensor is located near the wheel hub of the front left tire.
Q: What happens if I ignore this code?
A: Ignoring this code can lead to decreased braking performance and safety issues.
Q: Can I drive with the C0505 code?
A: While you can drive, it's not recommended as it can affect braking performance.
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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