C123E – BMW DTC

BMW DTC C123E – Right Rear Wheel Speed Sensor – Signal Too High

DTC C123E meaning on BMW

DTC C123E on a BMW indicates that there is an issue with the right rear wheel speed sensor, specifically that the signal being received from the sensor is too high. This fault code is related to the vehicle’s stability control system, as it relies on accurate wheel speed data to function properly.

BMW DTC C123E symptoms

Symptoms of DTC C123E on a BMW may include:

  • ABS warning light illuminated on the dashboard
  • Traction control system malfunction
  • Stability control system intervention or failure
  • Uneven braking or ABS activation under normal driving conditions

BMW DTC C123E causes

Common causes of DTC C123E on a BMW include:

  • Failed or malfunctioning right rear wheel speed sensor
  • Damaged wiring or connectors leading to the sensor
  • Corrosion or debris affecting the sensor’s performance
  • Faulty ABS control module

BMW DTC C123E seriousness

The seriousness of DTC C123E on a BMW lies in the compromised stability and traction control systems. Driving with this fault unresolved can affect the vehicle’s handling and safety, especially in adverse road conditions or emergency maneuvers.

How to diagnose DTC C123E on BMW

To diagnose DTC C123E on a BMW, you can:

  • Use a diagnostic scanner to retrieve the fault code and related data
  • Inspect the right rear wheel speed sensor for physical damage or contamination
  • Check the wiring and connectors for any signs of wear or corrosion
  • Perform a visual inspection of the ABS control module for any visible issues

How to fix DTC C123E on BMW

To fix DTC C123E on a BMW, you may need to:

  • Replace the right rear wheel speed sensor if it is faulty
  • Repair or replace any damaged wiring or connectors leading to the sensor
  • Clean the sensor and its mounting area from any debris or corrosion
  • If necessary, address any issues with the ABS control module

How to erase DTC C123E on BMW

To erase DTC C123E on a BMW, you can:

  • Use a diagnostic scanner to clear the fault code after the repair has been completed
  • Ensure that the underlying issue causing the fault code has been resolved before clearing it
  • Perform a test drive to confirm that the fault code does not reappear

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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