Hello and welcome to Just Answer!
Lets try this - Sit in the vehicle with all doors closed and starting with the key in the off position, turn it to ON, OFF, ON, OFF, ON (don't turn the key to the start position just on) within 5 seconds and leave the key on and watch the digital odometer to see if it displays a fault code. It will be a P followed by 4 numbers example P0700. When it is done displaying codes or if there are no codes it will say done. If you can't get this to work, please try it again following the instructions!
I did the code inquiry again and the code came back as "P0700" and than
displayed "-----" than "donE" .
We need to scan the PCM with a scan tool to see what transmission codes are stored. Would you be able to run near an Autozone or another parts store that will read codes for no charge? P0700 is just telling us a transmission code exists and it can't be retrieved with the key cycle.
Once you get the codes, post them here and we can go from there!
I will find an Auto Zone this morning and see if they can do that and respond back to you.
I did see to fuses/reley identified as Diesel Transmission one is in space #5 a big fuse or rely that is 3/8" square and 3/4" long and had a 30 stamped on end and the other in space #50 and is a 10 amp fuse. it appears to be good. Should i get replacement to try that?
No, I wouldn't do that is they appear ok. If there was a fuse gone, you would only have third gear(limp-in mode).
Do you know anyone that could read the codes again from the PCM? I don't think they were in the correct controller when they checked for codes because they should have for sure come up with P0700 along with the transmission related code.
Sorry for not getting back sooner, I am busy at work.
The PCM stands for powertrain control module which is the controller on the pass side firewall. ECM stands for Cummins engine control module which is on the left side of the block. The PCM is what controls the transmission on a 2004 Ram truck with the 5.9L Cummins diesel.
In 2003 Dodge trucks had both a PCM and ECM. In 2004 they went to just an ECM which controlled the transmission and engine controls.
I went to another Auto Zone store. They did the same thing. They plugged in their machine under the dash on the dirvers side. and it only said passed. They looked at me funny when I ask if they could read the PCM. They never heard of that. (You know we do live out in the sticks in Oregon. Some people around here are supprised when they hear you don't have to use a crank to start cars anymore). I will call around tomorrow to see if someone has a machine that can check the PCM.
Yes, I think they are related!
If you accelerate moderately from a stop, can you feel any shifts besides the torque converter clutch? Once you start driving and accelerate moderately and you reach 15 mph, pull the shifter into manual second then manual low to see if it downshifts. If the transmission is in limp-in mode it will only have third gear, but you will still be able to downshift manually.
It sounds like it's in limp-in!
This could be caused by a few things and it would be a good idea to get the transmission codes so we know where to start.