[Martin 335d]

I'm having a couple of minor issues with the gearbox in my 335d,

95% of the time the gearbox is fine, smooth shifts up and down the gears, but occasionally it will hold on to 3rd gear and when changing into 4th there's a slight jolt. Also it sometimes holds onto gears bringing the revs up to near 3k before changing up. If it starts behaving funny it's always when warmed up and on a steady relaxed drive.

I'm thinking the gearbox ECU software may need updated?

[briers]

No doesn't sound right if it revs that high in D.

Mine holds onto revs at around 2k RPM but that is when a DPF re-gen is active.


I would try a reset of the gearbox memory. But would wait until you get more info as this might be a known problem with a fix (i'm unaware of) and resetting the box memory might clear errors if you take it to bmw. Someone else will have to confirm.

But to reset

Key in, press start button (don't touch the brake), wait for dash lights to go out
Foot to the floor on accelerator for 30 secs
Turn off ignition
Release pedal
Wait 5 mins

Start car and drive normally.

[jonl1983]

mine was doing the same things between 4th and 5th. Is it quite a hard jolt when catching the gear? Have you had any warnings on your idrive?

Mine ended up needing a brand new auto box a couple of months ago because of this

[Dave_3]

Originally Posted by Martin 335d

I'm having a couple of minor issues with the gearbox in my 335d,

95% of the time the gearbox is fine, smooth shifts up and down the gears, but occasionally it will hold on to 3rd gear and when changing into 4th there's a slight jolt. Also it sometimes holds onto gears bringing the revs up to near 3k before changing up. If it starts behaving funny it's always when warmed up and on a steady relaxed drive.

I'm thinking the gearbox ECU software may need updated?

It could be a Diesel Particle Filter regeneration in process.

When that happens the gearbox will hang onto gears a little longer to allow revs to rise. On the open road you would probably never notice, but with a little stop-start variable speed driving it may be a bit more obvious.

If you have ever driven an older car on a choke, that is a similar feeling.

It shouldn't really jolt, but will feel ever so slightly laboured (the system is under load) with the gearbox allowing higher revs for a shift point. It will be different from your normal driving style.

D.

[Team Green2]

Are there any problems that can come from resetting your gearbox?

[briers]

As Dave says, it could be the auto regen

Are you sure it is in 3rd and 4th... at 3k RPM i'm pretty sure you much be doing some serious speed in those gears to notice this.

I notice it in 2nd going around town, the rev's will rise and yes perhaps not as seamless to change, followed by an unusually high RPM at cruise (about 1.8k - 2.2k), also followed by reduced MPG and sometimes a smell of burning sugar.

[briers]

Originally Posted by Team Green2

Are there any problems that can come from resetting your gearbox?

afaik all it does is force the box to re-learn the mapping based on your driving style.

I believe there is 4 maps in each mode, D and DS. The car should re-learn and adapt the mappings each time you start the car but i think this reset clears it all.


I've done it twice and haven't notice any difference either time. Others claim smoother shifts and even better mpg. For me there has been zero difference.

[HighlandPete]

I don't like the sound of the delays and jolt like changes, that is not normal.

Yes we can have regen' situations, also tyre wear/odd tread depths or bad prressure settings can cause gears to hold, but this doesn't seem to fit those parameters. But do check tyres/pressures. Costs nothing to do.

The reset doesn't make any real adaption value changes, that requires linking up to diagnostics. It does appear to do something on some cars, I'm more inclined to see it associated with the throttle adaptions being set to default.

The driver adaption of the gearbox can simply be broken by flicking the stick to sport, or a restart of the car, so nothing there in memory to reset.

HighlandPete

[Martin 335d]

Thanks for the replies folks,

Im fairly certain its between 3rd and 4th gear, but it certainly holds onto the gear and then changes up with a jolt,

What gets me is the car can behave normally for and halfway through a drive it will start misbehaving once or twice and then behave as normal again.

I certainly never noticed any similar happenings on my first 335d.

Tyre wear is not an issue as the car had new wheels and tyres fitted around 1500 miles ago, and since getting the car ive done several decent runs with it so i cant see it being a DPF regen?

The car has an Insured warranty and is booked in for a service on the 5th im hoping this issue will be covered?

[ram33]

mine jolts (snatches) in ds mode but is fine in normal d mode. i thought this was normal? does that mean it isnt?

[jonl1983]

A slight jolt may be there in ds but the change itself smooth. Mine had an extremely noticeable delay in changing up under acceleration followed by a loud and hard jolt and lurch when entering 5th

[dxb335d]

Yours was replaced Jon right?! How many miles did your car have when this happened?

[jonl1983]

Originally Posted by dxb335d

Yours was replaced Jon right?! How many miles did your car have when this happened?

yes it was mate, car was on about 62K when it was changed. Took them nearly a month as it was on 'backorder'.

just booked her in for her remap when i get back off holidays!!!!!

[dxb335d]

Good man, how many miles on her now?!

Had you re-mapped her previously?!

[jonl1983]

On about 66k, not had the remap before so looking forward to it

[seanblee]

Mine used to snatch in DS mode, or hold gears too long when lifting off then jerk when it upshifted - took it back to the dealer and they updated the software, which completely solved the problem. This was about 2 years ago though, so if your car is a 2009 or newer, I'd expect it to already have the updated software that fixes this issue.

[Martin 335d]

Originally Posted by seanblee

Mine used to snatch in DS mode, or hold gears too long when lifting off then jerk when it upshifted - took it back to the dealer and they updated the software, which completely solved the problem. This was about 2 years ago though, so if your car is a 2009 or newer, I'd expect it to already have the updated software that fixes this issue.

I dont really used DS as i find D adequate for 99% of the time i drive, but your symptoms in D sound exactly the same as mine.

Its a 2007 model, and its in for a service on monday so hopefully i will get the software done at the same time

[seanblee]

If you're still on the original 2007 gearbox software, that's probably it It's a known issue, so if you're under warranty, they should upgrade it for free.

[Team Green2]

Originally Posted by seanblee

If you're still on the original 2007 gearbox software, that's probably it It's a known issue, so if you're under warranty, they should upgrade it for free.

what happens if the warrenty has run out will they still update the software for free if not anyone know how much

[seanblee]

They'll charge for it - probably worth giving them a call to enquire first, but I have a feeling it's a ridiculous number of hours of labour (like 6 or so). If the warranty is expired, you might want to consider using an independent; the latest third-party diagnostic equipment is able to update the car's software and BMW are obliged to supply them with the updates. Birds BMW in Iver are probably not far from you: http://www.birdsauto.com/

[MJS]

I'm having the exact same problem with my 335d. Started 1 year ago when it was 2.5 years old. Holds on to gears too long when playing up. If I change to DS mode then revs don't change. If I put cruise on then auto box changes up. Only does it about once a week but really annoying. Engine sounds really 'hollow' when its doing it too. It's definitely not a cold start problem. Dealer doesn't have a clue cos no fault codes come up! They've reset the gearbox software but it doesn't make any difference.

[EssexIan]

Mine had very similar symptoms to the OP when I first got it, turned out software was a very early version and an update cured all the jerkiness and hesitation. BMW dealer charged £250ish for the update and diagnosis. A thorough auto transmission fluid change at a respected independent made things better still, this was at 50K miles and cost approx £450 inc fluid and new filter.

Ian