Computer not reading engine oil temp

[MoonshineTheJKU]

So here we go, so my original 3.8 v6 that i had threw a piston rod through the block while going 70 down the highway. I swaped in a 2008 3.8 dodge caravan engine in and swaped over all of the jeep engine components to make the caravan motor into a jeep motor (a fairly easy swap if youre looking for a cheaper alternative to putting in a engine that came from a jeep). Engine turned over first crank and ran good. The issue that I am having now is this. I took the jeep to the transmission shop to have it looked at… heres the sequential order of what has been going on and see if yall can help. This is an automatic transmission btw
-at first he said that the trans is in limp mode because the trans oil temp sensor isnt working (it was showing -4 degrees) okay fix it
- he got inside of the transmission and said that all of the clutches were smoked and the trans needed a rebuild. okay fix it
- he finished the trans rebuild and then said that the PCM was bad because the trans wouldn't quick learn and get out of limp mode. Okay got a new PCM
- new PCM (pre programed to vin) pluged in and he says that the trans quick learned right away, however NOW the engine oil temp is showing -4 degrees throwing the PCM into a “loop mode”
This has been where we’ve been for the past 2 weeks and ofc i would like to have my jeep back. Yes it sounds like an eletrical issue but my constituents is the engine oil temp was reading fine the day i brought him the jeep because i was right there when he was diagnosing the jeep with the OBD2 reader. What do yall think???

 

[mrjp]

Run

 

[Speartip]

So here we go, so my original 3.8 v6 that i had threw a piston rod through the block while going 70 down the highway. I swaped in a 2008 3.8 dodge caravan engine in and swaped over all of the jeep engine components to make the caravan motor into a jeep motor (a fairly easy swap if youre looking for a cheaper alternative to putting in a engine that came from a jeep). Engine turned over first crank and ran good. The issue that I am having now is this. I took the jeep to the transmission shop to have it looked at… heres the sequential order of what has been going on and see if yall can help. This is an automatic transmission btw
-at first he said that the trans is in limp mode because the trans oil temp sensor isnt working (it was showing -4 degrees) okay fix it
- he got inside of the transmission and said that all of the clutches were smoked and the trans needed a rebuild. okay fix it
- he finished the trans rebuild and then said that the PCM was bad because the trans wouldn't quick learn and get out of limp mode. Okay got a new PCM
- new PCM (pre programed to vin) pluged in and he says that the trans quick learned right away, however NOW the engine oil temp is showing -4 degrees throwing the PCM into a “loop mode”
This has been where we’ve been for the past 2 weeks and ofc i would like to have my jeep back. Yes it sounds like an eletrical issue but my constituents is the engine oil temp was reading fine the day i brought him the jeep because i was right there when he was diagnosing the jeep with the OBD2 reader. What do yall think???

I gotta be honest Never Ever heard of a transmission going into limp mode ?
A fault in a transmission can cause the Jeep PCM to go into limp mode just like a problem in the engine can cause limp mode .
Is that is the exact terminology mechanic used
“ transmission in limp mode”
Or did he say “ transmission is causing PCM to go into limp mode ?
I know I’m mincing words here but there is a massive diff .
There is a Transmission Control Module depending on year located in the PCM or under dash near steering column. Did he say anything about that ?
Transmissions and their electronic controls can be very complicated .
May want to get a second opinion from a specialist .
It blows cause you already spent quite a bit . But current mechanic seems to be finding a lot of “ while we were in there “ repairs.