Code U0154 on the 2022 Audi Q5 indicates lost communication with door control module 'B', typically the front passenger door module. This module manages all electrical functions specific to that door including window, lock, mirror, and ambient lighting.
Audi Door Module Network
The Q5 uses individual door control modules that communicate over a LIN bus connected to the main body controller. Each module manages window regulators, central locking, mirror adjustment and heating, puddle lights, and position status. Communication loss isolates that door from the vehicle's central control.
Feature Impact
With U0154 present, the front passenger door may lose power window function, lock commands may not work, mirror adjustment fails, and the central system cannot monitor door status (open/closed). The master switches on the driver's door won't control passenger door functions.
Diagnostic Direction
Door module problems are most commonly caused by broken wires in the door jamb where the harness flexes during door operation. Inspect this area carefully. The module itself is inside the door panel and can be damaged by water intrusion if door seals fail or window tracks allow water entry.
Repair Path
Check door jamb wiring first - repair any broken wires. If the module has failed, replacement requires VCDS or ODIS for coding. The new module must be configured for the specific door position and equipped features like memory mirrors.