In August 2020, Volkswagen / Audi received an inquiry about a gateway control module failure in an Audi Q5 vehicle in China. An inspection of the situation found that the gateway control module had gone into fail safe mode because of liquid entering the module from a rear bench seat spill.

The gateway control module has been programmed to go into a fail-safe mode when an implausible signal is detected in the control unit. If an implausible signal is detected, the gateway switches off its function in order to avoid unwanted vehicle reactions. The vehicle remains steerable and the brake system will work, but the engine will go into emergency mode and remains in operation with reduced power.

Audi performed a safety assessment to evaluate the potential conditions and consequences that could result from a power shutdown of the gateway control module due to liquid ingress. Audi also conducted a risk assessment which indicated that the risk of a liquid spill leading to a failure of the gateway control module is very low and rare over the lifetime of the vehicle. At the time there were only isolated cases in the North American region and all of them happened after an outside influence, mostly after a beverage spill. Audi continued to monitor the problem.

In March 2021, Audi experienced an increase in customer reports related to gateway control module failures on Q5 vehicles after a liquid spill. Audi conducted additional testing and continued to investigate a potential solution to be implemented in production and in the field. Due to single field cases alleging the failure without a liquid spill, an additional investigation was initiated to rule out other root causes for liquid ingress. In August 2021 Audi identified a potential manufacturing issue in the factory in Mexico. “Due to a programming error of a glue bead robot, an underbody seam may not have been sealed sufficiently and therefore allow water ingress from underneath in very rare cases when driving through heavy rain or deep puddles.” The adjustment to the robot was implemented immediately and analysis continued regarding the impact of this additional potential cause for liquid ingress.

The Audi Safety Committee began to issue a service campaign in order to install a protective cover for the gateway control module and to seal the underbody in the area of the insufficient glue bead, but after a meeting with Transport Canada and the Defective Product Administrative Center in China, the Audi Product Safety Committee re-evaluated their decision and decided to conduct a voluntary recall to fix affected vehicles.