BimmerFest BMW Forum banner

Bizarre Steptronic behaviour

3K views 19 replies 10 participants last post by  ZymurgyBMW 
#1 ·
I traded in my 05 M3 for an 07 328xi. Saving $300 a month and got something more functional in the snow. Had it for about a week when I ran into this.
If I brake firmly while in drive @ 45 or so, dropping to below 20 mph, then immediately stomp the accelerator the car is hopeless. It leisurely down shifts one gear at a time, so it takes over three seconds to get into 1st or 2nd!
If you immediately put it into drive sport mode while braking, there's no improvement. It still takes forever to get into a rational gear.
I've been to the dealer twice, they claim it's working as designed.
So BMW is selling a transmission that leaves you with a three second delay before you can move as punishment for hitting the brakes?
Anyone else experienced this? If I put it in manual mode and slam down the gears I can get going, but I've got a transmission that's less responsive than what you get in a Chevy truck?
 
#2 ·
That's weird, In my 328i I've never had that problem and I've done 45-20 brakes and floored it right after, the only delay I ever got was 1-2 for it to kick into 2nd gear and get higher revs.
With DS mode I think it's even a bit more responsive....just a little bit.

Unless there's something funky with the transmission electronics, might it have something to do with being an xi model?
Other than that I dunno anything else that could cause it, kickdown always puts me back into a good lower gear, quickly, to get revs.
 
#3 ·
Seriously thinking of getting rid of the car. Partly because it's not safe unless you know exactly what to do. I rarely lend it to anyone, so as long as I'm the only driver, I'll be slamming down the gears as I'm braking, so the safety issue is mostly moot.
I'm still thoroughly pissed that a company who prides themselves on performance and technology, citing 50-50 weight distribution, dual vanos cam timing, the first production hybrid magnesium and aluminum block, and is looking out for us by using the rain sensor not only to drive the wipers, but to automatically dry the brakes, yet missed something as fundamental as making an automatic kick down appropriately!

2007 328xi, Montego Blue over gray, premium, sport, CWP, steptronic (or is that stupid-tronic?)
 
#4 ·
I have often experienced downshifts occurring in two stages, with brief delays (both 330i and 335i) but nothing anywhere near as bad as you describe. Near the end of the pedal travel, you do encounter a resistance point, and pushing past it activates a special downshift switch. Check to feel that switch (can do with engine not running). Bunched up carpet or defective switch may be contributing to the problem.
 
#5 ·
I think that's normal. BMW programs the gearbox software to minimise fuel consumption, not for responsiveness anymore. I normally drive an 04 X3 with the older gearbox and it's better in almost every way than the dimwitted 6AT in my mom's 2006 325i. The lag when overtaking or merging is obscene even with it in sport mode or even when I use the kickdown (full-throttle position). But it's normal; you should have gotten a manual if you wanted responsiveness.
 
#6 ·
I appreciate the info, I'm certain I'm triggering the switch. If I haven't just hit the brakes, the kick down is quick enough, it still runs through the gears, just does it faster.
Vehicle is a CPO, picked up on March 12th. It may be on the for sale section soon.
 
#8 ·
Thanks, I've tried that as I'm braking, but not before braking. I've been simulating what happened to me that caused me to find this out in the first place: A moron pulled out in front of me into both lanes so there was no choice but to brake immediately, then once he committed to one lane, I got on it. In that particular case I couldn't have put it in sport mode before hand without being psychic. It will down shift manually, I just have to start doing it as soon as I brake if I think I might want power quickly. I'll try the beforehand method and see if it works.
I still have a problem with the trans not being able to figure out what to do when the car's only doing 10-15 mph, & I've floored it. What more does it need to know?
 
#9 ·
I still have a problem with the trans not being able to figure out what to do when the car's only doing 10-15 mph, & I've floored it. What more does it need to know?
............

That particular situation may be a problem. Full throttle downshift into first gear may cause traction problems, and traction control may get involved in cutting engine power. Of course, you have a 328xi, and the all wheel drive may help avoid traction problems. Hmmmm....... You, as the human behind the wheel, have a brain which knows how to make decisions. Computer processors, however sophisticated, can prove to be extremely stupid on occasions.
 
#10 ·
Make sure that the car has the most recent trans software updates. My X2 with the same trans did weird stuff until the car was updated to the latest progman with the trans update. You can also clear the adaptations and see how it is. hit the start button without starting the car. (foot off of the brake) hold the gas pedal all the way down for 30 to 45 seconds and then start the car and go for a drive. I had to do this once a month or whenever the trans would start doing whatever it wanted.
 
#11 ·
I may have to do that daily! (kdding)

I'll give that a try. The dealership checked all the software, there was no improvement, so they called BMWNA who they say provided them with new non-standard software for the DME & the Trans control unit.
They also cleared the "Adaptations". It seems to be a little more sporty in normal driving, and the Brake-punch-it-delay cycle went down a little. Still was three seconds last I checked.

I can't get out of the car without spending too much money, so I'll have to deal with it.
I'm not hearing anyone else say they're having this problem though.

Is there any indication when the trans resets? or just hold for 45 sec's and find out?
 
#12 ·
...I'm not hearing anyone else say they're having this problem though...
I think you're spot on with your observations based on my experience with an E90 328i and my current vehicle, the 335i. I think BMW's current design philosophy is that D is for leisurely, economy driving. I must add though that DS proved to be quite enjoyable for me in the 328i. In the 335i, I find myself having to use M (manual) mode most of the time to get the best experience from the car.
 
#13 ·
Thanks to all who responded.

Forgot to thank all of you who responded!. PLZ forgive me. :(
This is the best forum I've been on in a while.
If I ever figure out how to get past this issue I'll definitely post what I did.

I believe before the dealership made their changes, the transmission wasn't letting the power through until it finally got into the right gear. Now it seems to be accelerating a little as it steps down. I wonder if there's a software switch they've changed.
 
#15 ·
I'm gone for a week, I'll look for your post when I get back. I hope for your sake you don't have this issue.

Oh and just to add injury to insult, I caught a rock over the past few days that put a 3/4" diameter shatter spot in my windshield.:tsk:
 
#16 ·
I had same experience, don't sell it yet.

I bought a CPO 07 328xi sportwagon last year. I had the same experience that you are having. I was cussing at the steptronic left and right. I bought a sprintbooster off e-bay, which completely changes the response time of the slushbox. I couldn't be happier. It is very easy to install I take it off when I have it seviced doesn't leave any service code on the car. If you punch it it won't shift til redline. I have gotten so adapted to it that if I want it to shift at 4,000, 5,000 or 6,000 RPMs I know just how much peddle to give it. The bonus for me was how fast it downshifted with the situation you first discribed. I used to always go to sport mode in that situation, now I never do. When I bought it was $300 it was worth every penny. I also noticed that when I took it off temporarily for service that the computer had "adapted" to my driving habits and was better than when I first bought it.
 
#17 ·
Anyone else tried the "Sprint Booster'?

I read up on it. all it does is bring the voltage of the throttle position function up faster.
http://www.sprintboostersales.com/
it doesn't look like it could make much improvement. Even at the 0.3 seconds they show in the graph, stock is only 0.4 I'm trying to get better by 2 seconds or more, not 10 yards down a 3 mile long road.
 
#18 ·
Same person, additional info. On one previous question of the 10-15mph and the tranny trying to figure out what to do, the sprintbooter will add nothing to help find the right gear. I always put it in sport mode if I am going to accelerate after coasting at 10-15(example turning left across a divided highway).
I also tried the braking from 45-20 and punching it. Similiar results with or without Sprintbooster, it seem to be the Steptronics ackiles heal so don't buy the Sprintbooster for that you'll still be disappointed. I'll be honest I never really ran into that situation, I am lucky enough not to drive it in much stop and go traffic.
On the comment that David1 about "reseting the tranny" I tried that 3 or 4 time with no change, the sprintbooster definately "resets the tranny" nothing else worked.
The best way for me to discribe the difference between with and without the sprintbooster is that it gives the impression of a quicker 0-60, because the auto doesn't shift too soon if you don't want it.
I do not notice a difference when in sport mode while accelerating, but it definately down shifts much quicker when in auto down to around 30-35mph and I think it is near perfect while on the highway from 6th gear to 4th.
For me personally it was night and day. I also have a Passat with tiptronic and the steptronic is no where near as good as it, but the sprintbooster has lower my annoyance 90% of the time.
I hope this helps, I couldn't find much on it either before I bought it. Good luck
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top