What gear is your X in exiting a slow corner?

[X5Jay]

Originally Posted by jditom

This is what is on my invoice.

Reprogrammed ECS control unit as per SIB 240106
6100009.70

I will drive it around town this weekend and let you know about what gear it is in around corners at 20 mph.

Thanks for the info & looking forward to your next report!

[jditom]

Originally Posted by CGSTL

How about going around a residential corner at about 20MPH? Does it remain in 4th gear and bog down when you gently press on the gas to power out of the turn? Or does it properly drop down into 3rd when you get down into the low 20's MPH?
Thanks.

At 20 mph I am in 3rd gear when in D mode. I tried this multiple times on a level part of my city. If I give it gas it just ups the RPM's and stays in 3rd. No boging. If I slowly give it gas from 20 mph and go to 35-40 mph it will be in 5th gear.
So far I have been very happy with the software update. I still like the 5 speed tranny on my 2003 X5 4.4 better.

Get the upgrade!

[LVR]

At 20 mph I am in 3rd gear when in D mode. I tried this multiple times on a level part of my city. If I give it gas it just ups the RPM's and stays in 3rd. No boging. If I slowly give it gas from 20 mph and go to 35-40 mph it will be in 5th gear.
So far I have been very happy with the software update. I still like the 5 speed tranny on my 2003 X5 4.4 better.

Get the upgrade!

Keep in mind that after reprogramming you are in effect starting with a clean sheet. Your car is in fact learning from your driving style and is in the process of setting new values from scratch.

Any changes will likely manifest themselves after some time/miles ..............

[jditom]

Originally Posted by LVR

Keep in mind that after reprogramming you are in effect starting with a clean sheet. Your car is in fact learning from your driving style and is in the process of setting new values from scratch.

Any changes will likely manifest themselves after some time/miles ..............

Correct, my observations were after 2 days and 100 mile of driving.

[X5Jay]

Originally Posted by jditom

Correct, my observations were after 2 days and 100 mile of driving.

Still useful info though - thanks again!

[LVR]

found this on the E60 forum today.......

Talking to the dealer they tell me that the process of purely updating the software is not enough (info from BMW) and the adaptive box requires "re-training". To do this they need to run the car in top gear (above 70mph) and do a series of slow downs and slow accelerations, 10-15 cycles. This apparently then teaches the box to be more sensitive...! To be honest if correct this sounds like why people often experience an initial improvement after s/w upgrade. Then due to various driving styles the fault manifests itself again after time. All sounds like a real band-aid fix rather than getting to the root-cause.
As said, this is what he told me BMW Germany had instructed all dealers to do when upgrading software for transmission slam!

and this

This morning I took my car out with an engineer from ZF (who make the transmission) heis seconded to BMW UK to troubleshoot transmission issues.

He connected up a diagnostic kit to the plug in the drivers footwell to monitor the tranny whilst I drove.

We were able to reproduce the 'slam' to order by slowing to about 3 mph gradually and then just before coming to a halt, accelerating fairly briskly.

Almost every time the revs went up and after a delay the car picked up the drive and shot forward.

We could also reproduce another behaviour. When going down a steep hill, causing acceleration due to gravity with foot off throttle, touch and release the brakes. The car downshifts 2 gears, giving high revs, then accelerate again and you get quite harsh upshifts.

His explanation of the 'slam' was as follows.
The transmission is working 'normally'. The shift point is set up with a stop/go system so that as you drive in traffic the car does not drop below 2nd gear. This enables a smooth progress without unnessecary shifts into 1st. The normal pick up with gentle acceleration is easily achieved in 2nd.

The consequence of this set up is that if you suddenly ask the car for high acceleration levels it detects that it cannot achieve this in 2nd and selects 1st with a consequent delay. This has been measured by ZF as about 0.75 seconds, though he accepted it often feels a lot longer.
I pointed out that when pulling out into traffic which is travelling at 50mph, on oncoming car travels at 75 feet per second, so 0.75 of a second delay is not good news.

The only solution to the issue is to reset the shift points so that the car always selects 1st when the speed drops, this however would mean a huge number of 1>2 > 1 shifts in stop start traffic giving a poor ride and the risk of harsh low speed shifts.

The problem is exacerbated in larger diesel engines due to the high torque and the slight turbo delay.

The same process is present in petrol engines but is felt much less due to the faster response of the engine to the throttle and the lower torque at lower revs. hence it is often viewed as a diesel only problem. The greater the torque the more noticeable the behaviour. This explains why the 530D and 545i and up raise complaints whilst the 520i and 525D seem less prone.

The only way to mitigate the issue is to select DS which forces selection of 1st at low speeds, but be aware that you will feel harsher 2>1 shifts in traffic.

Every 5 series 'suffers' as do Jaguars, Audi's and others but due to different driving styles and road environments, some drivers will notice it more than others. It is especially noticeable if you are a frequent user of roundabouts where you often approach at a very slow speed the accelerate without coming to a full halt.

The downhill behaviour is due to the software detecting acceleration whilst also detecting a braking signal. It interprets this as brake failure and, as a safety system, initiates downshifts to provide engine braking.

The bottom line is that currently there is no 'solution' to the 'slam' issue, there is no software update beyond 17.10 that will have any direct effect on the tranny behaviour, though he does not rule out that at some time in the future there may be changes. There is nothing currently on the radar.

I have made my point that I am very unhappy that a £40,000 car does not have a better matching of transmission with engine and that this will probably be my first and last BMW if that is the quality I get for this kind of money.

I will now hit every car review website I can find to ensure that potential buyers of BMW's are made aware of this problem and are prepared to live with it.

[Steved]

I went through all this with my first 4.8is and lost count of the number of software updates it received and the times we restarted the adaptive learning process. At the time it was driving me crazy and I took out representatives of BMW UK to show them why it was unacceptable. Now, with my latest 4.8is none of these issues are evident, so I can only conclude that it 'is' possible to solve. I've got the ZF manual which I posted a synopsis on here (or was it bimmerF) about 18 months ago. It's interesting to read and understand why the autobox behaves the way it does.

To answer the question of this thread, my X is in 4th gear when exiting a slow corner that I entered from 5th. Depending on how slow the corner is I might change to DS so that 3rd is engaged, but there's usually plenty of torque to stay in 4th, unless I'm in more of a hurry.

Usually I drive using manual changes because then I can use X-drive to trim the line through the corner (and transfer power to the front wheels), otherwise I tend to stay in DS or in D for busy areas.

I never experience my gearbox holding on to a gear and revving up to 5000 rpm without changing, but the adaptive map will be based on a pretty sporty driving style. I drive my X faster than most people, and do so regularly, so I'm usually within the XS map.