BMW Repair: 2001 325i throttle motor, bmw dealers, engine computer

Question
I'm receiving a 'service engine soon' error message that indicates to mechanics that I need a new throttle motor/engine. Part cost $700. There is apparently a service guide on this particular message. What is a throttle motor and what are the 'symptoms'. This is a vehicle I just purchased received this message the next day. Please enlighten me.

Answer
Judy, Throttle motor part number is 13 54 7 502 444. Call into a couple of BMW dealers and see if they come up with the same price. The throttle motor assembly (EDK) is the component that lets air into the engine to be mixed with the fuel before it enters the cylinders to be burned. On your car (and most others since 2001) the throttle is no longer actuated by a cable connected to your gas pedal, it is activated electrically by the engine computer (DME) from the input of the electric gas pedal sensor (PWG). Therefore making it an electric motor (and really expensive). What repair shop are you at? Dealer? What are the fault codes that were read out? What Service guide are they appling? Who did you purchase the vehicle from? Does it have any warranty left? CPO?
-Evan