I have the same tranny (85 635 Euro 118k) and had the same problem. I cleaned all and replaced some battery connections + & -. Cleaned electrical connections on the side on the tranny. When the problem first appeared, my mechanic told me to remove the hot to the battery and replace it. This reboots the computor and it got me home. The problem has not reappeared, the tranny always and still shifts smoothly. Good Luck Jim Trans started shifting roughly on the highway. A few minutes later, the warning light came on on the dash (orange light, looks like a gear with a "!" in the middle of it). It is now stuck in third. Putting it in first second or drive doesn't matter. It stays in third. It will go into reverse, too, but it seems very rough when it does it. Its an 86 535i with the "123" electronic trans (same as E24). Q: Am I dead? The shop has been looking at it for 2 days now, hoping that it is just something electrical. But I'm not so hopeful. I fear its new transmission time.