97 BMW 540i erratic automatic shifting

1997 BMW 540I
130,000 MILES • V8 • 2WD • AUTOMATIC
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SDVMHV
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I have been trying to find rhyme or reason as to what or when this happens but i can find none. frequency at least once a week. When driving at steady speed usually between 30 -40 mph car starts 'hunting' for gears bouncing back and forth on RPMs and eventually with a big thud goes into failsafe mode. turn it off let it sit .. then its ok.. sometimes. sometimes it take a little while to go back to normal.. rest of the time works great maybe little slippage from 1-2 . I am thinking it is not mechanical since its not all the time. oh yeah and ASC, engine light and abs light all constant on
Jan 19, 2011 at 4:23 PM
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DOCHAGERTY
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The problem is what is called pendulum shifting. 24-07-98 is the BMW bulletin regarding the issue, it will require the EGS to be reprogrammed to update the software. The ASC/DSC ABS issue is most probably the control module has an internal fault, it is common and the repair usually requires replacement of the control module. Whew.. having spoke the party line I can now tell you in plain english what this means and what to do. The Electronic Gear Select (or whatever EGS means in German) is the brain for the transmission, it will require updating the software to correct the problem, at 130k I would also not be against a recommendation of replacement of the filter and the fluid. This operation is somewhat expensive due to the cost of the fluid, and it is special fluid that is unique to the transmission used in that car. It will prolong the service life. The ASC/DSC ABS issue might be a little bit more difficult to take due to the cost of the replacement unit and the need to code the unit to the car. Realoem.com sells them for a kings ransom, no fault of their own, they are just super pricey. And the part will be unique to the car and its productin date. The last 7 of the VIN will assist in this identification process. There are alternatives, let me know what you decide to do, I will be in the area all day, at ease and as you were! (military humor, if there is such a thing?)
Jan 19, 2011 at 5:44 PM
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SDVMHV
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Roger, That is the best explanation i have had. Thank you. So is this something i can do myself (the reprogramming) or do i need to go to BMW. again thank you. you mention alternatives to the ASC problem..any hints?
Roger Wilco
Jan 19, 2011 at 5:56 PM
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DOCHAGERTY
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You are going to have to seek out a repair facility (perhaps the dealer...) to have this reprogramming completed. As to the ASC/DSC issue, send me an email @ pghagerty@aol.com and include a phone number, I hate trying to type all of that, if you know what I mean.
Jan 19, 2011 at 7:58 PM