BMW DTC C120A – Wheel Speed Sensor Rear/Right Circuit Low
DTC C120A meaning on BMW
The DTC C120A for BMW indicates an issue with the Wheel Speed Sensor Rear/Right Circuit being detected as low. This means that the sensor responsible for monitoring the speed of the right rear wheel is reporting a signal that is below the expected range.
BMW DTC C120A symptoms
Symptoms of the DTC C120A on a BMW may include:
- ABS warning light illuminated on the dashboard
- Traction control system malfunction
- Unusual braking behavior, such as ABS activation under normal braking conditions
- Decreased stability and control while driving
BMW DTC C120A causes
Common causes of the DTC C120A on a BMW include:
- Faulty wheel speed sensor
- Damaged wiring or connectors in the wheel speed sensor circuit
- Corrosion or debris affecting the sensor’s performance
- Issues with the ABS control module
BMW DTC C120A seriousness
The DTC C120A should be taken seriously as it can affect the proper functioning of the ABS and traction control systems in the vehicle. Driving with this fault unresolved may compromise the safety and stability of the vehicle, especially during braking and cornering maneuvers.
How to diagnose DTC C120A on BMW
To diagnose the DTC C120A on a BMW, you can follow these steps:
- Use a diagnostic scanner to retrieve the fault codes from the vehicle’s ABS system
- Inspect the right rear wheel speed sensor for any visible damage or contamination
- Check the wiring and connectors associated with the wheel speed sensor for any signs of wear or corrosion
- Perform a resistance test on the sensor to determine if it is within specifications
- Test the sensor’s output signal using a multimeter while rotating the wheel to check for fluctuations
How to fix DTC C120A on BMW
To fix the DTC C120A on a BMW, you can try the following solutions:
- Replace the faulty wheel speed sensor with a new one
- Repair or replace any damaged wiring or connectors in the sensor circuit
- Clean the sensor and its mounting area to ensure proper contact and operation
- If the issue persists, consider checking the ABS control module for faults or seeking professional assistance
How to erase DTC C120A on BMW
To erase the DTC C120A on a BMW, you can use a diagnostic scanner to clear the fault codes stored in the ABS system’s memory. After addressing the underlying issue causing the fault code, clearing the code will reset the system and turn off the warning light on the dashboard.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.