Rudy

One of the nice things about the SMG is that's there's really no way to do it improperly. It won't let you shift in situations where the engine could be damaged, etc.

Madcole

Hi everyone,

Just found this sight today, looking specifically for this exact topic.

I have a 545 with SMG that I have put just over 5,000 miles on in the 4 months I've owned it. It would probably have more miles but it has been in the shop 6 times, will be the 7th next week, all for this one problem: (forgive the non-technical terms to follow): when I am driving, doesn't matter if it's in manual or auto, if I am on a steep decline (I drive the highways of Dallas back and forth to work, and if you live here you know that to go from one highway to the other sometimes requires rather large overpasses) my car will, quite frequently, shift itself from first gear into neutral, with no assistance from myself; the display still shows 1 or D1, but the car goes nowhere when the gas is pushed, but the tach shows the engine revving. The shift is preceeded by a rather loud noise similar to a mis-shift when a clutch is involved, which of course my car does not have. This has happened, I believe, just over 30 times, and it only happens when I am in first gear, driving in very slow, almost non-moving traffic, and as I said on a steep decline. Oh, and the best part: The only way I have been able to get the car back into gear has been to turn the engine off and restart it. Not a pleasant experience in rush hour traffic.

To date, my dealer (Classic BMW in Richardson Texas) has reprogrammed software, drove the car and shifted into all gears under 2500 rpms (?), reprogrammed the DME, reconnected and greased several different connectors, retaught the transmission (?), added some type of clips, and finally this last time they replaced the DME, each time declaring it fixed and ready to go. And this last time I was actually hopeful that it might be fixed, since they actually replaced something. That hope lasted about 15 minutes, as on my way back to work from the dealership the morning I picked it up, I got stuck in traffic, on a down slope, and you guessed it, same thing.

The delear has replicated this twice during their test drives, they have had someone from BMW NA come work on it, and supposedly they are having someone else come next week to do the same. They told me that they had not experienced this problem with the SMG transmission, but in reading last month's Motor Trend long term update on a BMW Z4 (page 150), it appears that that cars SMG transmission has been having a similar problem of sticking in neutral.

Obviously I am beyond frustration. Just wanted to share my story and see if anyone here has any knowledge of this problem, or any advice on what to do. The management at the dealership has been absolutley zero help, and BMW NA has been about the same.

I will say, that other than this problem, I love the car and have no desire to get rid of it, I just want it fixed. I read, with quite a bit of jealousy, of all the 545 owners out there who have had no problems and get to enjoy their cars on a daily basis.

Rudy

Sounds like, and forgive me if I'm using outdated terminology, there may be a weak "detent spring" that is causing the car to pop out of gear and into neutral when descending a hill. This used to happen to me a bunch in a really old manual transmission car I owned (not a BMW) back in 1980. The gear selector would simply pop out of gear and into neutral when there was back pressure on the trasmission (not under acceleration).

With the SMG, if the car popped into neutral (mechanically) without the software "knowing about it," the car would continue to think that it's in gear. If you were to attempt a shift using either the paddles or the gear selector, the software is probably trying to change gears since it thinks it's already in one.

That's my (limited knowledge) theory anyway! Good luck with the resolution of the problem and I guess the rest of us SMGers will keep our fingers crossed that it won't happen to us as well!!