Where is main computer of this car

VW PASSAT 2006-2007 2.0 TDI 170 HP BMR

Hi guys! I have an error light in watch but the led its working. I put on tester this car and i have many errors such like tire pressure, data bus can, etc. So.. someone tell me, maybe its water on connectors on main computer and i need to clean it. But i dont know where is! Can you help me? Thanks , have a nice day guys