rear hatch switch

hi all i have problem with my rear hatch. all was fine until a couple of weeks ago. when unlocking car switch will not open hatch but if i press button on key fob it opens. any ideas. also when my engine is runnig there is a hi pitch scream from the top at front of engine. after a while it reduces noise to half. when you turn off it carries on for a couple of seconds then stops. any ideas. local garage says its the throttle body assy? thanks chris