Dodge Repair: Dreaded LIMP Mode 1992 Caravan, tranny fluid, a604

Question
the only code i get is a bad TPS and i have changed it now to but the tranny still goes into limp at a stand still only if i disconnect the TPS it will not go into limp but without the TPS it will not shift properly ether
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Followup To

Question -
Like I said I took it in and they told me they can not get a reading from the tcm (THE DEALER) because there is no connection between the TCM AND the ECM I myself found that the eatx relay cuts the power to the TCM every time the van goes into limp mode and the relay has been checked and replaced with a new one even though it was working  
but I can not find the reason for the eatx relay to kick off I am thinking that the TCM might be shot but im not sure
Ted
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Followup To

Question -
finnally took it in for a code read but they tell me that they can not do it because it reads that the ecm and the tcm have no connection
PLEASE HELP
new input and another output since the last question
T
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Followup To

Question -
Ok here goes

I have a 1992 caravan with 246,000KMS on it, 6 cyc 3.3 and the dreaded a604 tranny.

Tranny was replaced (so im told) before I got the van and only has about 10,000kms on it

I have replaced the tranny fluid and the output sensor.

Now heres the problem when the van is started in the morning around 7am it works perfectly all the way to work about 30 miles,(van sits at work all day in the sun) But when i leave work after the day is done about 5:30, the van will drop into limp mode and no matter what I do it stays there even if i shut off the key give it a minite it still just drops back in to limp mode if not before I move it will go into limp mode (will even drop into limp mode waiting in line at the drive through coffe shop) in under 10 feet of driving.

Now if i drive it in limp mode at 80 k

Answer -
Ted,
You did not say how long this has been going on; but let me give you my input on this transmission.

Chrysler(1990-1993) needed a 4 speed automatic overdrive that could be "engineered up" quickly and chose to redesign the current 3 speed auto internally; the result is a transmission case that is FULL physically speaking, and in order to accomplish this, it required a fluid that was of a thinner and lower viscosity.

In other words, when they re-engineered this transmission, there was not adequate "room" for the fluid in it. What is required is that only one fluid will work in this transmission, and that is Mopar 7176.  Anything else will damage the transmission, because of its inability to dissipate internal heat properly.  If there is anything else in it, it must be completely flushed and refilled with 7176. You can only get this at the Chrysler dealer.

Now, to address the issue of the transmission not working properly later in the day....my educated guess would be that there are clearance and tolerance issues in the clutch packs of the transmission (assuming that you are already using the correct fluid) OR contamination issues regarding the valving that is computer controlled.

The reason that the ECM cannot read the TCM is because they are two seperate units and whomever checks the transmission must connect directly to the transmission TCM

Answer -
Ted,

Okay here goes............check the transmission solenoids for "going to ground" or open circuit;

the EATX supplies 12v power to the solenoid valves, but because they are only rated at 3 ohms, you cannot supply "constant" voltage; they operate on what is known as "pulse width modulation", PWM for short. The voltage is cycled on and off at VHF (very high frequency); enough that the solenoid will not "shudder" or vibrate.

About every 10-12 seconds the TCM monitors the solenoids to check for ground or voltage spike.  This is done by the computer sending a signal to the solenoid in a mere fractional of a second. If it detects "ground" or "spike", it will automatically revert to limp mode

Charlie

Answer
Ted,

I really appreciate the negative feedback; as you "feed" me bits and pieces of info / I have no choice but to give back answers as they relate to the questions. Mechanics and technicians are not miracle workers and cannot solve all of your problems for you.  If you do not need nor intend on following up on our advice then go trade your vehicle for a new one and "pay the price"

You are not the only contact that comes in; volunteers literally spend hours a week trying to help you and others solve their problems AND ALL FOR FREE.............  

next time, pick another expert, or when you go to the dealerships....do what they ask and pay what they charge !