Audi notes that if a TPMS warning light illuminates on a 2007 A4, S4 or Avant vehicle, and various DTCs are stored (voltage supply, no/low antenna signal, etc.), check to see if the vehicle’s windows have been tinted.
On vehicles where window tint film was installed, it is possible that water entered the tire pressure control module during the window tint installation. If you encounter a vehicle with a tire pressure control system failure and the windows are tinted, check if the failure occurred shortly after the window tint was installed.
Inspect the control module and wiring connections for signs of water damage before servicing any other components.