BMW 740il 1999 Erratic Computer

Alarm LED displayed Trans Prob-Failsafe after 30 minutes after driving approx 30 minutes (speeds 35 to 80 mph). Also begin displaying (intermittently) warning lights for brake (lining), ABS, DSC, and check engine. Finally, I noticed that the speedometer and tach were not working at various intervals. Sometimes the a/c compressor would shut down.

I then made an appointment with a reputable BMW independent mechanic who decided that the transmission must be faulty. Then I took the car to his recommended transmission shop, Aamco. Aamco tested the car and determined that the transmission was ok. They even observed the car returned to normal during a portion of their road testing.

On their recommendation, I had the car towed to the dealer. The dealer had the car over the weekend but was only able to get to it by the following Tuesday. Now, three days after the dealer was able to start his investigation, no one has any answers to the problem.

What do you suggest?

Make BMW
Model 740il
Year 1999
Mileage 95K
Engine Size V8 4.4l 282hp