osama

I recently purchased an 06 550i with Stepronic. I've been driving it in DS mode 100% of the time. I noticed a strange behaviour with my transmission that lead me to send the car back to the dealership and for them to replace the entire transmission. Unfortunately the new transmission is doing exactly the same thing. Here is the what happens:

Accelerate up to highway speed ... 80+ Km/h will do it ... once at highway speed decelerate smoothly back to a complete stop. My car will downshift from 5th to 4th to 3rd to 2nd (around 30 Km/h) and then it will *UPSHIFT* to 3rd for a second or so before downshifting back to 2nd. The upshift to 3rd is accompanied by a distinct transmission shifting noise and a sudden drop in RPMs to 1000. Very annoying behaviour. I returned the car to the dealer again and was given a 550i loaner with 500 KMs on it ... guess what ... it does the same thing.

Anyone else notice this behaviour? would love to hear from other 550/545 owners.

Many thanks in advance,
Osama

0700700

not much help, but i had a 545i loaner with auto tranny last summer and it did not exhibit any behaviour like this so it seems very strange...

but to have it on 2gearboxes and 2 different cars ?

sjc550

I might be having the same problem. The transmission in my car seems to shift up and down while slowing down from 45mph or so. It's more like it just isnt quite sure what gear it wants to be in. It ends up staying in a gear that I feel is a little low for the situation. If i lift off the gas pedal just barely the car slows due to engine braking and then if i barely push on the pedal it lunges. Very hard to drive smoothly!!! Also runs kind of rough for the first 10 minutes or so after starting.

I have an appointment for it on Wednesday for CIP 20 to be installed. Hope this fixes both issues!!

znod

Hi Osama:

I am glad you still are around, but am sorry that you are having the same significant problem. Except for what is said above, I have not heard of anyone having the problem but you.

tachyon

I have not noticed this pattern. I'm traveling for a few days and will try it out in my 550 when I get back.

If anything, I would say it is a software issue, not mechanical.

osama

I agree ... it most definitely looks like a software issue. My entire transmission was replaced which means that it is not mechanical. The issue seems to happen only in DS mode and only when you slow down from Highway speeds down to 20MPH. But once you get the car to do it you will become keenly aware of the problem and you will notice it every time.

Osama

Bimmer32

I don't drive much in DS mode but read your posting very carefully. I will try it in the next couple days and let you know. I have a 545i 3/05 production date with no software updates yet.

Dirty 30

I'm surprised the dealer replaced the transmission over those symptoms. the odds of it being mechanical were by far outweighed by it being software related.

colejl

Agreed - just shows how much the dealers understand about our cars!!!!

znod

Agreed - just shows how much the dealers understand about our cars!!!!
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I would imagine that the dealer either tried a software fix first or, through previous experience, knew that software would not fix the problem,