X5 throttle adaptation not met.

[amerc]

2002 X5 3.0L, 140,000 km. Error says that "throttle adaption not met." Indy mechanic changed thottle body three times, and also changed the throttle pedel. Two months later I'm still getting the same error message, and now he tells me I need to change my ECM computer. Last night I put the throttle pedel to the floor, and turned the ignition key. The error message cleared, and the car runs fine. If ECM is not holding adaptation why was I able to run the car again? Can someone tell me if this is possible, or is my indy mechanic taking me for a ride. Thanks for your help.