BMW DTC C123D – Left Rear Wheel Speed Sensor – Signal Too High
DTC C123D meaning on BMW
DTC C123D on a BMW indicates that the left rear wheel speed sensor is reporting a signal that is too high. The wheel speed sensors are crucial components of the vehicle’s anti-lock braking system (ABS) and traction control system. They monitor the speed of each wheel and provide this information to the vehicle’s electronic control unit (ECU) for proper operation of the ABS and traction control systems.
BMW DTC C123D symptoms
Symptoms of DTC C123D 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 C123D causes
The most common causes of DTC C123D on a BMW include:
- Failed left rear wheel speed sensor
- Corrosion or damage to the sensor or its wiring
- Faulty ABS module or ECU
BMW DTC C123D seriousness
DTC C123D should be taken seriously as it can affect the proper functioning of the ABS and traction control systems. Driving with a faulty wheel speed sensor can compromise the vehicle’s stability and safety, especially during emergency braking or slippery road conditions.
How to diagnose DTC C123D on BMW
To diagnose DTC C123D on a BMW, you can follow these steps:
- Use a diagnostic scanner to retrieve the fault codes from the vehicle’s ECU
- Inspect the left rear wheel speed sensor and its wiring for any visible damage or corrosion
- Perform a visual inspection of the ABS module and ECU connections
- Test the wheel speed sensor using a multimeter to check for proper resistance and signal output
How to fix DTC C123D on BMW
To fix DTC C123D on a BMW, you can try the following solutions:
- Replace the left rear wheel speed sensor if it is found to be faulty
- Repair or replace any damaged wiring or connectors related to the sensor
- If the issue persists, consider checking and potentially replacing the ABS module or ECU
How to erase DTC C123D on BMW
To erase DTC C123D on a BMW, you can use a diagnostic scanner to clear the fault codes stored in the ECU. After performing the necessary repairs or replacements, you can reset the system by erasing the fault code and retesting the vehicle to ensure the issue has been resolved.
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
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