Transmission Activity

We're greatly enjoying our 2007 Odyssey EX. One thing I'm confused
about, however, is the transmission 'activity'.... By that I mean that
it seems to downshift when you take your foot off the gas and are
slowing down. This is confirmed by watching the tachometer tick upwards
as you feel the transmission downshifting. Since our last van was a '99
Windstar (I was happy when it would simply UPshift!) and my other car
is a 6-speed Audi A4, I guess I'm not used to the electronics in the
latest transmissions. Is this really the case - that the car
downshifts? Or is my transmission about to fall out!

Thanks.

Dan D
Central NJ USA
'07 Odyssey EX

 

Dano58, wrote the following at or about 1/2/2007 2:29 PM:

I noticed the same thing with my 2006 Accord EX. Read the owner's
manual, at least I think that's where I read it, and there was an
explanation that made sense to me. It DID take some getting used to
though. No doubt about it.

IIRC, the computer senses a number of things including braking, incline,
etc and decides whether to just let you coast or to downshift to provide
extra braking. Now, with 8,000 miles under my belt on the car, I rarely
notice it.

 

Yep, they downshift.

It is used to help your brakes last longer, and to help aggressive braking
stop faster.

This is a good thing.

 

It called "Logic Grade" , that is why you won't grind
up your rotors..read up on it.

 

I would think that it would hurt your gas mileage though. At least it
would if you are anticipating a stop and just want to coast until the
light changes. Is it possible that it waits for you to touch the
brake pedal before it downshifts? That would make more sense.

On the upside, completing the downshift earlier makes it ready to
accelerate on short notice. All-in-all, that is one reason why I
prefer manual transmissions. The AT will never have enough sensors
until they put in one that can read my mind.

 

which is precisely what it does do - it takes the signal from the brake
pedal switch.

you haven't driven an automatic lately.

 

Your tranny is fine.

The extremely sophisticated electronics installed these days have
considerable control over shift behavior. In addition, the transmission
will actually "learn" your driving style and adjust its behavior for that.

Some people find newer transmissions' behavior disconcerting when compared
to older designs.

The very best thing you can do for your transmission is to change the fluid
precisely according to the maintenance schedule, and to ONLY ever use Honda
genuine ATF-Z1 fluid. If you want to change the fluid MORE often, that's
even better.

 

Thanls for all of the responses. I figured it was a function of these
intelligent transmissions. Of course, I could read the manual but every
time I think about it, the car isn't actually here....!

Dan D
'07 Odyssey EX
Central NJ USA

 

Thanks for all of the responses. I figured it was a function of these
intelligent transmissions. Of course, I could read the manual but every
time I think about it, the car isn't actually here....!

Dan D
'07 Odyssey EX
Central NJ USA

 

I wish they would supply a flow chart or other documentation.

J.

 

Take the Manual in the house, then when you're in the reading room, you
can find out all about the vehicle.

 

My understanding is that the cars do learn how you drive. Now, I'm not
really a car guy, but I'm a computer programmer. I can certainly see
how the computers could learn how you drive and act on it, but it
would also need to understand that a car can have more than one
driver. Until you actually have to log-in, it might get confused. Now
is this the guy with the lead foot or the lady with the sweet
disposition?

Perhaps they'll start using retinal scans or fingerprint detectors on
the steering wheel. It should be a good theft-prevention model, until
you try letting your designated driver take you home and it won't
start. And then it won't start for you because you're drunk.

Maybe we'd best forget the whole idea.

 

Well, I'm sure they have improved somewhat since they made the one for
my '98 Ody, but I would be surprised if they now know in which gear I
want to do compression braking. I'm pretty sure they don't downshift
in anticipation of me wanting to do hard acceleration two seconds
before I touch the gas pedal. How does it know that, even though I am
doing a steady 40 mph, I want to stay in second gear to be ready to
make a move in traffic? Does it know not to downshift just before we
crest the hill? For my Ody, I would be happy if it just didn't
downshift when I hit Resume on the CC 4 mph below the target speed. I
would hope they have at least fixed that.

Bottom line is they are OK for average (or worse) drivers in light
traffic. But I definitely don't like them in heavy city traffic and
they just don't belong in any sports car IMO.

 

no, they provide a handy little lever that allows you to take care of
that by hand.

see above.

press the brake and you'll find out. they have grade control logic.
increasing speed + zero gas = downshift.

tell that to porsche - last i heard, their autos were faster than their
sticks.

 

Right, you can force the downshift or hold the gear manually but a.
then its not automatic and b. it is clumsy to shift especially on the
steering column.

My comment is that the transmission downshifts when I dont want it
too, i.e. just before cresting the hill when I would manually just
stay in the higher gear for a few more seconds.

That is because most Porsche buyers are people who want to show off
how rich/cool they are and don't really care about driving it or even
know how.

 

I would agree that they do not belong on any sports car, but IMO, the only
time I really WANT an Auto is for heavy city traffic.

 

but don't say it can't hold a gear because it can! you can leave it in
full auto or you can manually over-ride - the ultimate in choice. i
agree with you about column shifts however - i can't stand them.

dude, you said auto's couldn't hold a gear - they can. and grade logic
means they select the right gear, certainly a good deal better than some
of the individuals that pop up here from time to time putting their
sticks into neutral and coasting down hills. modern autos are not only
programmed to shift right, they also learn what the driver likes.

eh? how does criticizing [without basis] driver skill address the
ability of a computer-controlled transmission to shift faster than a
stick? makes no sense.

bottom line, you're welcome to drive whatever you want, but don't
criticize autos on the basis of fud - it's simply not justified.

 

Sorry, I misread the post. I thought you were saying that the ATs
were *selling* faster than the MTs.

My preference for MT is not based on how fast it shifts but rather the
ability to integrate the shifts seamlessly into driving. This
requires decisions based on information that the computer cannot
possibly know. May not matter much for a minivan, but it is
fundamental for a sports car.

The problem with most (virtually all) ATs is that they are biased
toward automatic operation and discourage manual operation. Also, I
don't particularly care for the slippage of the torque converter. I
understand that VW has a paddle shift AT that is actually built like
an MT. This has potential if the AT function can be completely
disabled, i.e. it never makes a shift without a command from the
driver. (Not that I would buy a VW under any circumstances.)

fud?

 

It depends on your attitude. For me, the only joy in "stop and go"
traffic is seeing how far I can go without touching the clutch or the
brake. When traffic is heavy but moving, I like the control that I
get from an MT.

 

that's your perception. unless you've driven a modern auto, especially
a sports auto, you're just making uninformed assumptions and using them
as your basis for criticism.

how? my auto has the shift in exactly the same place as where the stick
would be. i see no difference. the transmission even has a no-lock
gate between 3rd & 4th [commonest manual override] especially so you
/can/ flip up and down at will.

eh? what "slippage" is that? how does its mechanical function differ
from a clutch [other than it has a much better efficiency range and is
much smoother of course]?

as are a lot of the euro "autos".

dude, have you ever driven an auto? you have pretty much full control
over everything except clutching action - except for the fact that it
won't let you select wrong gears of course.

fear. uncertainty. doubt. if there is no technical argument against
something, people resort to fud.

here's another nugget for you - automatics are banned from f1. like
certain types of ground effects, they gave too much advantage to the
[better funded] teams that had them. the compromise is paddle shift,
but even then, interpretation of the ban has been taken to the limit
since a lot of the control functions are still automatic.