M-DCT Semantics and Subtleties

[BTWoody]

just curious, when I turn the car off, DCT engages park, does this engage rear brakes or holds the car in gear?

[SamS]

Originally Posted by BTWoody

just curious, when I turn the car off, DCT engages park, does this engage rear brakes or holds the car in gear?

Neither.

Loss of hydrolic pressure takes the DCT out of gear and engages a pawl inside the transmission.

[Arcades]

Originally Posted by CuryousGee

Wonder why a few comment on putting to neutral to park, every time i do that i get an error message but when i pull into a parking spot in gear , stop , then pull the hand brake and press the stop button, it automatically goes to park.

Never works on neutral, tired a few times. Only used neutral once when i was switching driver and needed to get out of the car and even then parking brake was engaged

Don't put Neutral to park. Leave it in Gear D or R, pull Hand Break, let go of Break Peddle, Press Start/Stop once to turn everything idle, then press Start/Stop again to turn everything off.

Ever read some reviews where reviewers complain about the M's DCT not engaging Park right away? That's because they put the car in Neutral and try to engage park that way.

I did it in R once, leaving the car in R before turning things off. Got a bit confusing when I started my car since I forgot I had it in R

[dclowd9901]

Originally Posted by mkoesel

This may be true, but have you ever wondered what catches the car as it rolls back? It's a course-toothed gear inside the transmission with a small catch or pawl that gets rotated and locked into place when the car is turned off. But as you can probably imagine, this isn't the most robust way to keep a ~2 ton vehicle in place. So, while it's generally true that the car will stay put without the emegency brake applied, it's a good idea to use it anyway. This way, if the car were to get struck accidentally it would be less likely to roll away. Plus, why put all that stress on the park lock? Using the brake will help distribute the load away from that small mechanism.

Interesting. I always thought it was the same thing that kept the car in place if you left it in first while off on a manual: the amount of force required to overcome engine compression was too great so the car doesn't move. I assumed this, of course, changed if the car is sitting on a hill.

[JenWil]

That was one of the questions we asked the our delivery specialist when we did PCD. Our CA advised us to put the car in neutral and then turn the car off when we test drove an M4. When we took delivery of the M3, the hubby asked and she stated the car actually doesn't like being put in Neutral when you go to turn the car off. She said to just leave it in gear, pull the handbrake and turn it off.

The times I have had the car in Neutral and went to turn the car off, I always get an error message.

[mkoesel]

Originally Posted by dclowd9901

Interesting. I always thought it was the same thing that kept the car in place if you left it in first while off on a manual: the amount of force required to overcome engine compression was too great so the car doesn't move. I assumed this, of course, changed if the car is sitting on a hill.

Many people assume this since they think of the DCT as a manual transmission internally. But it isn't really the case, especially when it comes to the clutches. As I explained in another post above, they will open when the car is turned off and the transmission fluid is no longer under pressure.

[secretariat]

I've had the car for almost a year now and only once did I use the emergency brake. The only difficulty people should be having is if you need to leave car running and jump out for a minute to get the mail or whatever. If that's the case pull the emergency brake and leave it in neutral. Or just step on brake hit stop start and the DCT will go into Park (P). It does take a little time to get use to it only because it's new technology for us US drivers, who are so use to seeing P on our shifters. It will be second nature in no time.

[ChrisJay]

The delivery specialist during my ED did suggest to use the parking brake every time it is parked to keep any unnecessary stress off the transmission. So my process of stopping to park was; pull into where I was going to park->pull parking brake->hit on/off button (while my foot was still on the brake). Pretty easy and not sure why some people make it out to be so tough. Although I will say explaining to a valet who doesn't speak your language can be tricky.
I will say (I know it sounds stupid) it took a few times to remember the process but by the middle of the trip, it was becoming the norm. I attribute it to the fact that during ED your mind is already 8 levels of blown due to jet lag, restless excitement for the big day finally being there, actually getting to finally drive your car, driving somewhere new (for those of us who it was new to), unfamiliar (and often very tight) streets (soooooo many bikes, trams, pedestrians everywhere), generally being in a place that is foreign to you where communication (and reading signs) sometimes is difficult, etc etc.

[Xerxes480]

Originally Posted by ChrisJay

I will say (I know it sounds stupid) it took a few times to remember the process but by the middle of the trip, it was becoming the norm. I attribute it to the fact that during ED your mind is already 8 levels of blown due to jet lag, restless excitement for the big day finally being there, actually getting to finally drive your car, driving somewhere new (for those of us who it was new to), unfamiliar (and often very tight) streets (soooooo many bikes, trams, pedestrians everywhere), generally being in a place that is foreign to you where communication (and reading signs) sometimes is difficult, etc etc.

So true!

I always use the e-brake. Better to be safe than sorry.

-X-

[Jamesomania]

Originally Posted by Blksnowflake

Why would you accidentally go forward, unless you had a mechanical transmission/brake failure...read the manual, pretty sure it instructs you to just turn the car off, not go into Neutral first. You come to a stop in gear, "foot on the brake", turn car off, car flashes [P] and powers out. If you want you can use the hand brake before or after this motion which doesn't really effect operation but neutral shouldn't be involved.
But regardless, you can get it into [Park] using the method you describe but you will have to press the button multiple times since the vehicle does not have a physical [P] button to go into park....anybody ever crank the engine back on after turing it off....thats why...

The problem with us is we're all programmed like a bunch of labs rats to fidget with some control or gear lever when coming to a halt. This has now given us a sense of securing the vehicle....BMW has taken this small step away so now we "feel" like we "need" to do something to "ensure" the vehicle doesn't somehow barrel away out of control killing woman and children. #justturnitoffbra

coming from E92 M3, once you come to a full stop, you put the car in Neutral, then press power button and it puts the car in Park mode, the difference now is you cant do that with new gen F8X Ms.

so it was a bit confusing to me when i did this, stop the car, put the car in Neutral, pull the E-Brake, push the power button, get out of the car, try to lock and honks, but same scenario with E92 M3, works.

not sure why they changed it for new Gen M3/M4.

[MasterC17]

Originally Posted by afadeev

On all recent bimmers, including F80/F82, parking brake manually engages the same rear caliper and pads that are used during regular braking (there is no inner parking brake drum shoe anymore).

False, this is only true for vehicle with the Electric e-brake (E70/F01/F08/F15/F25). F30 including F8X still have rear brake shoes.

http://www.realoem.com/bmw/enUS/show...diagId=34_2208

[997usa]

Originally Posted by boi222

I always pull when parking since there is no actual P button until you shut off the car... so i treat it like a manual car... put in Neutral, pull handbrake and then shut off the car

you can't lock the car that way - it will beep - so how do you lock it?

[boi222]

Originally Posted by 997usa

you can't lock the car that way - it will beep - so how do you lock it?

Press power (on/off) twice .. Either method on here works... I just prefer this method as i tend to leave the car running a lot while waiting so I'm used to it

[afadeev]

Originally Posted by MasterC17

False, this is only true for vehicle with the Electric e-brake (E70/F01/F08/F15/F25). F30 including F8X still have rear brake shoes.

http://www.realoem.com/bmw/enUS/show...diagId=34_2208

Oh wow, my winter beater MINI re-uses rear calipers for emergency/hand brake actuation, but M3 still has drum parking brakes?

Wow.

a

[dunny247]

All m cars I've had with DCT will not let you lock the car if it's left in neutral. Can't comment on f80 as I'm waiting for delivery. Don't know if that's applicable in usa but it definitely is the case here in uk.

[rexb16]

the transmission is not a kickstand kids.

[lifebeatson]

Originally Posted by bmw246

Thanks guys. My M4 just got off the boat yesterday. I have been waiting since the beginning of April. My first ///M

Wow I did my ED in April and picked up my car June 22nd. Longest 9 weeks ever. If I were you I would have freaked! Welcome and congrats. My first M too.

Always use the e brake unless on the track kids.

[afadeev]

Originally Posted by dunny247

All m cars I've had with DCT will not let you lock the car if it's left in neutral. Can't comment on f80 as I'm waiting for delivery. Don't know if that's applicable in usa but it definitely is the case here in uk.

It is the case for US-cars as well.

I caused a bit of a scene in downtown Munich during ED, when I parallel parked the car, put on the hand brake, then tried to lock it only to get alarm blare in return. Took me a few repeats of the above sequence before I figured out what was wrong. By that point I had attracted a small crowd of locals (who were likely taking bets on how long it will take the tourist idiot to figure out how to lock his new car).

a

[aboulfad]

Is there a way to stop the DCT from downshifting? Often, when I am slowing down and am in 3rd, I go to downshift only to find out that at the same time the car downshifted to 2nd and instead i end up downshifting to 1st! Of course the rev match sound nice but I don't think it's good to downshift to 1st at 15-20km/hr.

[mjcecil]

In reality, these are questions you will have for about five minutes once you own the car.

I never owned any sort of automatic transmission until I bought my E60 M5 with the SMGIII. The concepts with my DCT-based M3 are virtually identical, and learning how to use either took almost no time. It's startlingly intuitive, and you'll figure it out pretty quick.

mjc

[scrammer]

Originally Posted by 335d JTD

As per M4/M5 user manuals this can now be done as follows:

(An automatic car wash is the example used)

Note:
P is engaged automatically:
▷ After the engine is switched off in ignition
off, if position R or D is engaged.
▷ If the ignition is switched off and position N
is engaged.


Double-clutch transmission:
1. Drive into the car wash.
2. Engage transmission position N.
3. Switch the engine off (pressing the start/stop button while depressing the brake, switches off the engine but not the ignition).
In this way, the ignition remains switched
on, and a Check-Control message is displayed.
Do not turn off the ignition in the car wash;
otherwise, the transmission position P is
engaged and damages can result.◀

PLEASE do not put your ///M through an automated car wash!

[scrammer]

Originally Posted by aboulfad

Is there a way to stop the DCT from downshifting? Often, when I am slowing down and am in 3rd, I go to downshift only to find out that at the same time the car downshifted to 2nd and instead i end up downshifting to 1st! Of course the rev match sound nice but I don't think it's good to downshift to 1st at 15-20km/hr.

Yes … run it in manual mode not Drive.

If you are in drive, or auto mode, the second you push the stick forward or use the downshift (minus) paddle the DCT switches to manual mode … therefore … pick one or the other!

Rev-matching is cool but the only reason to downshift into a corner is to be in the correct gear when you accelerate beyond the apex - downshifts are not to be used in place of braking or trail-braking.