Yipes! Good luck with all of that, Dr. Kewl!

Hoping it's an electrical problem, but in the case that the transmission is fubar, check these guys out. They're in Sacramento; i think they might be the largest bmw salvage yard in the country:

http://www.data.bmrparts.com/bmwpart...70189765U.html

junkyard or somebody who totalled their X5 but if tranny is intact might be cheaper.

I have used them before....great service....I had replaced my E30 325i rear diff with a used limited slip diff.....my open rear diff was working fine, but was getting noisy despite fluid changes....so I upgraded to a limited slip rear diff and the first one they sent me eventually got noisy and then, they sent me another for free (under their great warranty) and it did fine for about 100K miles until I got rid of the car.....

Thanks for the advice....

They are located outside of Sacramento....Rancho Cordova I believe...

heard the dinana software shifts agressive and can damage the unit, to my knowledge bmw does not rebuild dtransmissions, they replace the unit with a new one and send yours out to get rebuilt to see where the fault was. dont go to one of the big transmission franchise companies like aamco, or lee myles etc...go to a local area that would charge less than $3000 anything less than that is a good deal. i was in the same situation last summer...when i got the slightest idea my transmission might be slipping, i purchased an aftermarket warranty for $2500... and it just sso happened my transmission did go out, and they completely replaced it...but if you go that route...i would make sure they cover actual cash value...oops..u already might be of knowledge of a problem...n/m ;) pm for any quesitons
good luck

yup. whole row of junkyards there of all makes and models.

bump, for any updates

Thanks....no word yet....

However, here are interesting PDF files about BMW Automatic transmissions.....

http://www.bmwmotorsports.org/BMW_docs/electran1.pdf
http://www.bmwmotorsports.org/BMW_docs/transfund1.pdf

My X5 3.0i has the A5S390R and you can see how they break down the model#....

A for Automatic
5 for 5-speed
S for top gear overdrive
390 for the fact it can handle 390 N-m torque
R for GM hydramatic (made by GM in France)

Also, you can see all the electronics control, diagrams, etc.

Here is the update: the local mechanic states that it appears that there is nothing mechanically wrong with the tranny so far.....At least the tranny can go into reverse and drive and it still moves foward, abeit slowly...

The error code is related to a sensor malfunction....the tranny cannot tell what gear it is in....He tried clearing the code and then when he drives the X5, after being in 1st gear, when it tries to shift, the tranny doesn't know what to do and then goes right into 5th gear (trans. fail safe mode).

So, any suggestions?:confused: There is an auto trans specialist for BMW & Mercedes in the local area and we are going to get it checked out with them....

Did he remove the Dinan software programming for the transmission before he test drove it? Maybe that might help. :dunno: