So, I've got over 80k miles on my '05 MCSa and I started to have some minor issues with rough up-shifting a couple of weeks ago. A little annoying, but nothing a huge issue in my mind.

As of yesterday, it got a bit worse. After being on the highway for about 30 miles, I exited and pulled onto a side street. After pulling away from an intersection, the car started got to 3rd gear and just stuck, revving until I manually shifted it into 4th. I had to use manual all the way home, and still felt rough upshifts (though no sticking) out of 3rd, even in manual.

This morning on the way to work, it seemed to have quelled itself a bit -- I was able to drive in Auto mode without having any real issue (though I didn't really drive hard at all). This afternoon on the way home, in Auto mode, I definitely get a stutter/lurch going from 3rd gear to 4th. Doesn't really happen when shifting up out of other gears.

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**UPDATE** Drove to work this morning and the stutter/lurch started happening towards the end of my drive (all side roads) when I would accelerate a bit more to get out into traffic. And it's still mainly when going from 3rd to 4th, but I may have had an instance of it happening from 4th to 5th.
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So, I'm left wondering what the hell is going on? Anyone have any ideas? Is it a software issue? Does the transmission need the fluid changed? Is this just an early sign of the transmission going out????

 

If it is a software problem it will usually display "EP" , otherwise the problem would be mechanical. If a battery disconnect doesn't reset it, a trip to the dealer is in order.

 

Check the tranny fluid level, The torque converter and valve body can cause bad shifts as well.

 

This occurred with me (would not upshift out of 2nd and when manually engaging it, there was a pause). This eventually tripped the stability (triangle and ! warning), ABS, and flat indicator lights. Thought there was a problem with the ECU, however, it turned out to be a problem with the ABS/speed sensor wire that was frayed. Got it changed out and all is back to normal.

 

Any lights/codes?

Like ej, I had an issue with a wheel speed sensor wire that caused all sorts of havoc with the transmission and DSC.

 

Thanks everybody!

No lights, and I haven't had it hooked up to see if it's throwing any codes. I'll check the tranny fluid levels and see if I'm running low.

The speed sensor sounds like it could be the culprit, but as I haven't had any lights flip on yet, I'm not convinced just yet.

I'm thinking if I can get it to be fairly repeatable, I'll take it into the dealer.

 

The Aisin is a "sealed" unit - no dipstick to check level. BMW says the fluid is "Lifetime."

 

**UPDATE** Drove to work this morning and the stutter/lurch started happening towards the end of my drive (all side roads) when I would accelerate a bit more to get out into traffic. And it's still mainly when going from 3rd to 4th, but I may have had an instance of it happening from 4th to 5th.

 

Oh yeah, I'd forgotten about that. Dang it.

 

Hook it up to a CAM BUS scan computer. they give WAY more info than a standard OBDII scanner. might have codes there that dont throw lights

 

80K, factory fill? Could be a clogged ATF filter, fluid that is low (which is highly unlikely unless you can see evidence of leakage) or simply ATF that is in need of a change.