I have a 1998 grand caravan...i noticed, when i first start up and take off slowly and accelerate it will go thru the gears...if i first start it up(cold) and hit it mid. acceleration, it doesnt go thru all the gears....if i let the van get warm and go easy it will go thru all the gears...after it warms up i can hit it and feel it going thru all the gears...like a normal car should....

i havent gotten the trans codes yet and not sure where to get this done as of yet, i dont have tags on the van as of now, so i cant really take it anywhere...im too poor to pay for a bunch of parts but i was wondering what the TCM is for and what it does....

 

The Transmission Control Module shares information with the Powertrain Control Module and as you guess, TCM and PCM. These modules will share data to allow the correct shifting points. So if you loose a sensor or any other problems, the check engine lamp will come on and let the tech know if its a transmission problem or an engine problem. Is the check engine lamp on? How cold is it where you live, Because weather below 32 degrees will cause shifting problems.

 

i cleaned the underneath of the van which was terribly nasty and the wires going in and around the trans are the same....i need to clean them some more and change the fluid( sorta on the dark side, im tryin not to say 'burnt' but not bright color as out of a fresh can) also, the fluid seems to be above the high side...i can see where mechanics hate going behind someone else's 'fixes'...

yes, the engine light is on.

 

Okay, I need to know the codes. This way I can send you or post the information to you.

 

AutoZone or the like will read your codes for free. If the only transmission related code is a P0700, it means the transmission controller (TCM) has stored a code and that code can only be read with a specialized scanner capable of reading transmission codes. That means a trip to a shop.

 

This cold operation trouble is an extremely common issue shared by most higher mile, aging 4spd caravans. It is only an annoyance. If you baby it instead if hitting it, the tranny will likely behave that way for the next 10K to 100K mi until an overhaul is eventually necessary. If it's like mine, the symptom vanishes when cold after driving about a mile. Soon as my tranny warms a bit it behaves like new. I would strongly suggest that you take it easy when cold so the transmission does not fail prematurely. The line pressures are wrong in the cold valve body due to sticking seals, valves or seal blowby. This symptom surfaces when seals are stiff like a frozen wiper blade and fluid is cold and thick. The transmission can't take much load or abuse when cold, so don't "hit it". It only has to reach 50 degrees F or so for these cold symptoms to vanish. Some don't like to downshift into first when coming to a stop. This problem is exaggerated when folks fail to come to a complete stop at an intersection. The tranny stays in second and will slip if the throttle is depressed hard at slow speed. In other cases, it may not upshift soon or at the proper time.

 

Thank you....at this moment, everything is on hold for a bit....New job Monday, out of town.

I will be coming back here soon...Thanks again.

 

i am taking it easy and going to follow all your advice here....soon as im able to get back to this project...thanks you much!

 

"We" are fortunately not having the cold weather most of the North is having...i let the engine warm up a bit before i drive it slowly....

I'll update soon...

Thanks guys!

 

My post assumes no check engine light. You should investigate the check engine light as Master Tech suggested to fix that issue and see if it's related to your symptoms.