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 reading the speed of the left rear wheel when the car starts moving.
The code C120E indicates an issue with the left rear wheel speed sensor, which is responsible for detecting the speed of the wheel as the vehicle starts to move.
The C120E code is triggered when the wheel speed sensor on the left rear wheel fails to provide accurate speed data to the vehicle's anti-lock braking system (ABS) or traction control system during the initial drive-off phase. This can affect the vehicle's ability to properly control braking and traction.
• ABS warning light on
• Traction control light on
• Inconsistent braking performance
• Faulty left rear wheel speed sensor
• Damaged wiring or connectors
• Malfunctioning ABS module
ABS: Anti-lock Braking System
OBD-II: On-Board Diagnostics II
• Inspect the left rear wheel speed sensor for damage
• Check the wiring and connectors for corrosion or damage
• Use a diagnostic scanner to read sensor data and confirm the fault
• Replace the faulty wheel speed sensor
• Repair or replace damaged wiring or connectors
• Reset the ABS system and clear the code
• OBD-II scanner
• Multimeter
• Socket set
$100 - $300
Moderate
• Toyota Camry
• Honda Accord
• Ford Fusion
• Regularly inspect wheel sensors for damage
• Keep sensor areas clean and free of debris
• Check ABS system during routine maintenance
Sensor Issue
• Avoid hard braking until the issue is resolved
• Drive cautiously as traction control may be impaired
Check with your vehicle manufacturer for specific warranty coverage on ABS components.
Wheel speed sensor issues have been common in vehicles with ABS systems, often due to sensor wear or exposure to harsh conditions.
Moderate – It is important to address this issue soon to ensure proper braking and traction control.
Driving with a faulty ABS sensor can compromise vehicle safety and may not comply with road safety regulations.
• Vehicle must be on a flat surface
• Ensure the vehicle is in a safe location to perform tests
The left rear wheel speed sensor is located near the wheel hub on the left rear wheel.
Q: Can I drive with a C120E code?
A: It is possible to drive, but it is not recommended as it may affect braking and traction control.
Q: How do I reset the ABS light after repair?
A: Use an OBD-II scanner to clear the code, or disconnect the battery for a few minutes to reset the system.
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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