Strange problems, need help.

[elpitha33]

Our 2003 3.0 x5 has recently developed a strange problem. 3 times in the past month it will just shut itself off, also occurring is delayed engagement of the transmission after it has been sitting. We took it to the dealer who says that both problems are being caused by a faulty throttle valve motor as well as a faulty engine compartment wiring harness. ($1540.00). They claimed there is a tsb about this but I find it hard to believe that both parts failed at once and think they just want to throw everything listed in the tsb at it at my expense. Does anyone have any experience with this problem or a possible more realistic solution? The TSB is FIB121002. Thanks in advance for any and all help.