2003 Gr Caravan 3.3 trasmission question

Hi
Sometimes, when coming to a stop but not fully stopped, after I release the
brakes and press the gas it feels like the tranny is stuck , Then by
pressing the gas it get unstuck . Is this normal. It happens once in a
while. I also get the bump feel one in a while to too coming to a stop
Tx

 

Not normal, and the two problems are probably related. Get it to a
competent transmission diagnostician. Probably a small/inexpensive fix if
you address it *now*, probably a bigger/more expensive fix if you wait.

 

First thing to try is AT fluid change with the right fluid. Many places use
the wrong fluid for Chrysler AT's or the use the right CHrysler fluid with a
3rd party additive. Insist on Chrysler fluid per your manual with no other
additives.

 

The Van has 22000 miles, no AT fluid has been changed yet. I service it at
Chrysler so far. So it still has the original fluid.
Tx

 

Have you double checked the fluid level?

 

Is it happening right at 5 mph + or - a couple? And when you pop back on the
throttle you get a bump or hard shift? They do have a propensity to do this
at these times as it's just initiating a shift from 2nd to 1st and than you
take off again. Also do you change drivers alot? Say back and forth from you
and the wife or SO. It does "learn" drivers and for a little while will be a
little strange. Otherwise have someone run a diagnostic. Probably would not
hurt to do a fluid/filter but most likely not necessary yet.
Larry

 

Heh heh!. On the 300M Enthusiasts Club forums, the opinion was
occasionally expressed that the "learned" condition eventualy becomes
sluggish and strange-behaving under certain driving conditions. A year
or two ago, a "how to" was posted on adding a relay in the power center
in the 300M to cut power to the TCM when the ignition was off to revert
back to the unlearned state each and every time time the vehicle was
started. I thought about doing that on my Concorde.

The OP might try pulling the fuse for 20 minutes to see if accummulated
and confused learning is the problem. Occassionally resetting by
pulling the correct fuse might be a solution.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

 

I don't think that's a good idea as it not only learns shift patterns but
clutch volumes etc. and making it go through this all the time may not be a
"good thing" ;-)
Larry

 

Which may be why he removed the "how to" from his link.

I'm glad you mentioned that though. When I had my Concord's TCM
reflashed a couple of years ago due to a firmware update, after the tech
finished that, they told me it would be a few minutes more for him to do
a "calibration" (that's the word they used). I asked them what that
was, and they said that it did things like calibrate the cup volumes
(maybe they said clutch volumes, but I thought they said cup volumes).
Anyway - I was left wondering if that was some special operation they
performed in addition to the firmware upgrade and the resetting of the
TCM, or if it was in fact an inherent result of them resetting the TCM.

Can you shed some light on that?

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

 

Basically it's a function performed with the DRB called "quick learn" and it
helps the TCM "learn" how much fluid it takes to fill the clutch packs
during application. Known as "CVI" or "clutch volume index" it's one of the
things a tech can look at to help diagnose the health of the trans.
Larry

 

Thanks for the explanation

One more thing about that - you said in the previous post that "it not
only learns shift patterns but clutch volumes etc." (referring to what
happens after resetting the TCM). Would it be correct to say, as far as
the clutch volume calibration, that the DRB "quick learn" and the
learning that would otherwise occur after resetting the TCM are the same
(again, I'm asking only in regards to clutch volume calibration)? IOW -
the DRB quick learn just gets that part of the learning out of the way.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

 

THe quick learn just sets safe baselines based on what the DRB "reads" at
the time. When you drive off settings are "adjusted" to your driving styles
and the actual road conditions etc.
Larry