Setting up the aux will be easy ;
just use a gp output , set switch off timer to 3s and use 'cond. 1 or 2 AND 3'
set cond 1 to your di for the manual switch
set cond 2 to your di for the auto switch
set cond 3 to IAT temp> value and set the value you want.
If you want more than just IAT then set cond 3 to virtual aux and configure the virtual aux with the conditions you want (say maby 80% throttle , speed above 50kph and IAT above 70)
if you would wire the aux through a double pole relay(30 would go to the pump,87 to the aux,87a to nothing,85 to switched 12v and 86Â through your level