Alright guys, wrap your minds around this, because I need help.

I have a 200 dodge ram 1500 4x4 off road with the 5.9

Firstly my original trans ate up the front band and crapped out so I had a used unit rebuilt with a new torque converter. (the old unit's hard parts were all out of spec due to the front band destruction).

Right from the get go I've had PCM problems, from NO BUS on the dash to 3.8V bus to the trans (supposed to be five) and incorrect sensor readings due to a bad 5 volt + bus.

So I replaced the PCM, from there I've had the following issue. When you clear the codes, the truck will run in reverse, drive and so forth...however it stays in first. If you ramp it all the way to the PCM set max shift point it WILL shift to the next gear, let off the throttle and you have third...and even overdrive works, so does the o/d switch it will come in and out of O/D like it's supposed to...as soon as the trans finds its way back to first, this process repeats itself. By the third time it will set a code P1762. As soon as the check engine light comes on I lose first and have only second and third manual select only (no automatic shift function at all, otherwise known as limp mode.

At this point I decided something wasn't done right in the rebuild, took the pan off, inspected everything visually, checked the actuators and so forth for correct engagement with air pressure (as per FSM) and continued on with a off the truck test of the governor pressure solenoid. I replaced the solenoid regardless of finding no fault. I did not replace the transducer, it tested out correctly according to the FSM.

I reassembled the trans, replaced the pan gasket, filter and buttoned it up, took a little over six quarts to get it to the correct level. This time I started getting P1757 codes on the third start up, or the third time the truck shifted to park, once again the trans only had first unless it was run up to redline where it WOULD shift, and without a CEL at that.

So again, I broke out the code reader so I could watch live data. I observed the idle tps at 10.7% and WOT as 77.9%. I checked this out further by testing the input at 5.1V, which is well within tolerance. Beyond this I tried replacing the TPS, followed by setting the TV cable, replaced the spring for it as well since it was quite weak. From this point NOTHING in operation changed.

Then I read here that the upstream o2 sensor is on the same bus as the governor solenoid and it might correct itself if I unplugged it. I tried this, no change other than the codes you get for unplugging the sensor, this and the sensor works correctly it was changed a couple years ago. I also checked that circuit for short to ground and found none. During the trans replacement I cut off the pigtails to both the neutral switch and trans and spliced in a new one for each, the old ones were soaked in trans fluid and while the wires were very brittle the insulation was VERY soft, so soft i could peel it off with my fingernail.

Other things to note, I used atf+4 as it calls for, I flushed both the rad cooler and the external with diesel fuel...lines included, which resulted in alot of material finding its way out of both. I ditched the check valve and replaced it with a 3/8" trans cooler line w/ hose clamps.

I have not tried a pressure test, I haven't checked it out on a DRB and I'd rather not take it to a shop, if anyone has advise, or any possible reasons I am still encountering this problem I'm all ears.

 

Is the scan tool capable of reading the pressure of the governor solenoid/ pressure switch? The harness in the pan is known for rubbing against other components and creating a short. I would replace the solenoid and switch with new.


BTW, I don't see any mention of the TV cable? This thread provides directions to set it to factory position.https://dodgeforum.com/forum/2nd-gen...-in-trans.html

 

Harness is new as is lock up and o/d solenoids, scan tool cannot look at pressure reading or temp, I had to do that by observing output voltages

 

I'm not talking about the TC and OD solenoids. Those codes are for the other two. And what about the TV cable?

 

the harness (including gov and transducer were all attached to the same harness that runs those solenoids which all came together, so yess all wiring inside the trans is new. TV cable works correctly through it's length of pull, and returns.

 

The harness is connected to the TC lockup and OD solenoids, the Gov pressure switch and solenoid are separate plug in devices. That's great that the TV cable moves in and out, but, is it adjusted correctly? You don't just slap it on you know.

 

Unplug the 8 pin connector on the drivers side of the trans. Take the truck for a ride. You will have ZERO automatic functions, you will HAVE to shift manually. Run the truck up and down thru the gears a time or three. Everything work as advertised? Replace the pressure transducer. Just because it tests good in one circumstance, does not imply that it is good under ALL circumstances. They are notorious for failure.

If they were replaced when the trans was redone, that also is no guarantee of good parts. if the rebuilder used reman parts, you may have gotten bad ones right there. That, and the remans don't last long either...

 

Umm! That just sounds like a bunch of jibberjabber to look smart if you ask me.

 

Dammit zman, don't give away my secrets like that.

 

I'm gonna guess the rebuilt trans wasn't a 2000 or 2001 model. If that's true, theres your problem.