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 how fast the right rear wheel is moving when you start driving.
The vehicle's ABS system uses wheel speed sensors to monitor each wheel's speed. Code C120F indicates a problem with the right rear wheel speed sensor's ability to recognize speed when the vehicle begins to move.
The C120F code is triggered when the ABS module detects an issue with the right rear wheel speed sensor during the initial drive-off phase. This sensor is crucial for providing accurate wheel speed data to the ABS, traction control, and stability systems. If the sensor fails to provide accurate data, these systems may not function correctly.
• ABS warning light on
• Traction control warning light on
• Inconsistent braking performance
• Faulty right rear wheel speed sensor
• Damaged wiring or connectors
• Malfunctioning ABS module
ABS: Anti-lock Braking System
OBD-II: On-Board Diagnostics, second generation
• Inspect the right rear wheel speed sensor and wiring for damage.
• Check for loose or corroded connections at the sensor.
• Use a diagnostic scanner to read ABS module data and confirm the fault.
• Replace the faulty right rear wheel speed sensor.
• Repair or replace damaged wiring or connectors.
• Update or replace the ABS module if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $300
Moderate
• Toyota Camry
• Honda Accord
• Ford Fusion
• Regularly inspect wheel speed sensors and wiring.
• Avoid driving through deep water which can damage sensors.
• Keep the vehicle's undercarriage clean to prevent debris buildup.
Sensor Issue
• Avoid hard braking until the issue is resolved.
• Drive cautiously, especially in wet or slippery conditions.
Wheel speed sensors may be covered under the vehicle's basic warranty or extended warranty plans.
This code has been more common in vehicles with high mileage or those frequently driven in harsh conditions.
Moderate – While the vehicle may still be drivable, it is important to address this issue to ensure proper braking and safety system functionality.
Ignoring this code may result in reduced braking performance and could lead to unsafe driving conditions.
• Vehicle must be driven to initiate the drive-off recognition.
• Ensure the vehicle is on a flat, safe surface during testing.
The right rear wheel speed sensor is located near the brake assembly on the right rear wheel.
Q: Can I drive with a C120F code?
A: While you can drive, it's not recommended as your braking performance may be compromised.
Q: How do I reset the ABS warning light?
A: Fix the underlying issue first, then use an OBD-II scanner to clear the code.
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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