BMW DTC U1235 – Message Monitoring Status TCM via FA-CAN Signal Error
DTC U1235 meaning on BMW
DTC U1235 on a BMW refers to the Message Monitoring Status Transmission Control Module (TCM) via FA-CAN Signal Error. This diagnostic trouble code indicates a communication error between the TCM and the FA-CAN (FlexRay-CAN) network in the vehicle.
BMW DTC U1235 symptoms
Symptoms of DTC U1235 on a BMW may include transmission shifting issues, erratic behavior of the transmission, illuminated warning lights on the dashboard related to the transmission system, and potential limp mode activation where the vehicle operates in a restricted performance mode.
BMW DTC U1235 causes
The causes of DTC U1235 on a BMW can vary and may include faulty wiring or connectors in the FA-CAN network, a malfunctioning TCM, issues with the FA-CAN bus communication, or software-related problems within the TCM or other control modules in the vehicle.
BMW DTC U1235 seriousness
DTC U1235 should be addressed promptly as it can affect the proper operation of the transmission system in the BMW. Ignoring this fault code may lead to further transmission issues and potential safety concerns while driving.
How to diagnose DTC U1235 on BMW
To diagnose DTC U1235 on a BMW, a diagnostic scan tool capable of reading manufacturer-specific codes is required. The technician should perform a comprehensive scan of the vehicle’s control modules to identify the source of the communication error between the TCM and the FA-CAN network. Additionally, a visual inspection of the wiring and connectors related to the FA-CAN system should be conducted to check for any visible damage or corrosion.
How to fix DTC U1235 on BMW
Fixing DTC U1235 on a BMW may involve repairing or replacing damaged wiring or connectors in the FA-CAN network, addressing any issues with the TCM, ensuring proper communication between the TCM and other control modules, and updating software as needed. It is recommended to follow the manufacturer’s diagnostic and repair procedures outlined in the service manual for the specific BMW model.
How to erase DTC U1235 on BMW
Once the underlying issue causing DTC U1235 on a BMW has been resolved, the fault code can be cleared using a diagnostic scan tool. The technician should access the fault code menu on the scan tool and select the option to clear the stored codes. After clearing the code, it is advisable to 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
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