What is the fan that runs by itself in the front of the intake system and connects to the egr Valves 2001 S430, fan was running after shut off for about an hour two tubes do connect to the egr valves from this fan does anyone know what it is and why does it run by itself with engine warmed up and is shut off???? / Had someone look at my 2001 S430 and they said the relay stuck and cuased the secondary air pump to burn up have anyone heard of this problem before and how many electrical problems can i expect with this BENZ / am still ASE cert. have been in the service industry fro over 30 years. need some help here. thanks