Two liquid-entry paths
Volkswagen Group of America’s December 8, 2021 report describes liquid entering the gateway. Spillage on the rear seats is the main known scenario; water entering from below through an inadequately sealed body seam during heavy rain or deep puddles is separate. Neither is universal proof of cabin flooding.
Volkswagen Group of America / NHTSA repository: Part 573 Safety Recall Report 21V-947 / Audi 90S9
Applicability and the full analysisSeveral warnings do not mean several failed modules
The document explains that implausible signals can disable gateway operation, interrupt communication and produce several messages. Not every system showing an error is physically damaged. The described engine operates at reduced power while steering and braking remain available according to the manufacturer.
Volkswagen Group of America / NHTSA repository: Part 573 Safety Recall Report 21V-947 / Audi 90S9
Applicability and the full analysisFull material about the model
Audi Q5: liquid near the gateway and body-seam inspectionThe documented Q5 electrical mechanism, spilled liquid versus water from below, and limits after body repair.