BMW DTC U1809 – TCM Lost Communication with HIM (Hybrid Interface Module) via HL-CAN
DTC U1809 meaning on BMW
DTC U1809 on a BMW indicates that there is a communication error between the Transmission Control Module (TCM) and the Hybrid Interface Module (HIM) via the High-Speed Controller Area Network (HL-CAN) bus.
BMW DTC U1809 symptoms
Symptoms of DTC U1809 on a BMW may include:
- Transmission shifting issues
- Loss of hybrid system functionality
- Warning lights on the dashboard
BMW DTC U1809 causes
Common causes of DTC U1809 on a BMW include:
- Faulty Hybrid Interface Module (HIM)
- Wiring or connection issues between the TCM and HIM
- Software glitches
BMW DTC U1809 seriousness
DTC U1809 should be addressed promptly as it can lead to drivability issues and potential safety concerns. Ignoring this fault may result in further damage to the hybrid system components.
How to diagnose DTC U1809 on BMW
To diagnose DTC U1809 on a BMW, you can follow these steps:
- Use a diagnostic scan tool to retrieve the fault codes
- Check the wiring and connections between the TCM and HIM for any visible damage
- Perform a communication test between the TCM and HIM using a diagnostic tool
How to fix DTC U1809 on BMW
To fix DTC U1809 on a BMW, you can try the following:
- Inspect and repair any damaged wiring or connections between the TCM and HIM
- Update the software of the TCM and HIM to the latest version
- If the Hybrid Interface Module is faulty, replace it with a new one
How to erase DTC U1809 on BMW
To erase DTC U1809 on a BMW, you can use a diagnostic scan tool to clear the fault codes stored in the system. Once the issue has been fixed and the codes cleared, perform a test drive to ensure that the fault does not reoccur.
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.