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 can't tell how fast the left front wheel is turning when you start driving.
The vehicle's control module is unable to recognize the speed of the left front wheel when the vehicle begins to move.
This code indicates that the ABS (Anti-lock Braking System) module has detected an issue with the left front wheel speed sensor signal during the initial drive-off phase. The sensor is not providing a valid signal to the module, which is critical for the ABS to function correctly.
• ABS warning light illuminated
• Traction control light may be on
• ABS may not function correctly
• Faulty left front wheel speed sensor
• Damaged or corroded wiring or connectors
• Faulty ABS module
ABS: Anti-lock Braking System
OBD-II: On-Board Diagnostics II
• Inspect the left front wheel speed sensor and wiring for damage.
• Check for corrosion or loose connections at the sensor connector.
• Use a multimeter to test the sensor's resistance and signal output.
• Replace the left front wheel speed sensor if faulty.
• Repair or replace damaged wiring or connectors.
• Replace the ABS module if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$100 - $300
Moderate
• Dodge Charger
• Jeep Grand Cherokee
• Chrysler 300
• Regularly inspect wheel speed sensors and wiring.
• Avoid driving in harsh conditions that can damage sensors.
• Perform regular maintenance checks.
Sensor Issue
• Do not ignore the ABS warning light.
• Have the vehicle inspected by a professional if the light is on.
• Avoid driving in conditions that require ABS until repaired.
Check with the vehicle manufacturer for warranty coverage on ABS components.
This code is commonly associated with vehicles that have had ABS sensor issues due to environmental exposure or aging components.
Moderate – The vehicle can still be driven, but the ABS may not function properly, which can affect braking performance.
Driving with a malfunctioning ABS system can increase the risk of accidents, especially in poor weather conditions.
• Vehicle at initial drive-off
• Normal road conditions
The left front wheel speed sensor is located near the left front wheel hub assembly.
Q: Can I drive with a C120C code?
A: Yes, but be cautious as the ABS may not function properly, affecting braking performance.
Q: How do I reset the ABS 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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