BMW DTC U124C – Lost Communication Master-ECM With Slave-ECM Interconnection 5
DTC U124C meaning on BMW
DTC U124C on a BMW indicates a communication error between the Master-ECM (Engine Control Module) and the Slave-ECM (another control module in the vehicle). This error code specifically points to a lost communication issue between these two modules, affecting the interconnection system.
BMW DTC U124C symptoms
Symptoms of DTC U124C on a BMW may include:
- Check Engine Light (MIL) illuminated
- Engine performance issues
- Transmission shifting problems
- Reduced fuel efficiency
- Vehicle may go into limp mode
BMW DTC U124C causes
Common causes of DTC U124C on a BMW include:
- Wiring or connection issues between the Master-ECM and Slave-ECM
- Faulty ECM or control module
- Interference from other electronic devices
- Software glitches or programming errors
BMW DTC U124C seriousness
The seriousness of DTC U124C on a BMW depends on the underlying cause and the impact on vehicle operation. Ignoring this code can lead to further damage to the vehicle’s systems and components. It is recommended to address this issue promptly to prevent potential safety hazards and costly repairs.
How to diagnose DTC U124C on BMW
To diagnose DTC U124C on a BMW, follow these steps:
- Use a diagnostic scanner to retrieve the fault codes
- Inspect the wiring and connectors between the Master-ECM and Slave-ECM
- Check for any loose connections or damaged wires
- Perform a communication test using diagnostic tools
- Verify the software versions and update if necessary
How to fix DTC U124C on BMW
To fix DTC U124C on a BMW, consider the following:
- Repair any damaged wiring or connectors
- Replace faulty ECM or control modules
- Ensure proper communication between the modules
- Update software and perform programming if needed
- Clear the fault codes and perform a test drive to confirm the issue is resolved
How to erase DTC U124C on BMW
To erase DTC U124C on a BMW, use a diagnostic scanner to clear the fault codes stored in the system. After fixing the underlying issue causing the code, perform a reset and ensure the code does not reappear during subsequent driving cycles.
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.