I drive or 03 Ram 2500 5.7 Hemi with the 545RFE I believe. I’m not exactly sure what tranny it is but that’s my education guess lol.

But anyways, I was driving the other day and out of no where at around 30ish MPH’s accelerating, it shifted hard. Didn’t think to much about it other then it was weird but decided to go about 0.5 miles down the road and stop and check everything. So I Threw it in park and checked to make sure nothing was wrong and didn’t find anything out of the normal. The transmission fluid was a little dark but that wasn’t nothing new and it didn’t smell burnt or anything. Got back in and threw it into drive and started to move and it acted like it was slipping. Once it got out of first, no problem but I got a PO700 code that popped up and that was it. Got it home and threw it in park and shut it off for literally a minute and got back in and the slipping was gone.

Now, this is two days later. It was acting perfectly fine so I went to go tow a buddies truck home. We hooked up and started to two mile trip back and all seemed well. No codes or nothing. Got it all the way back and unhooked it and the same thing happened. Acting like it was slipping in first gear and also a new burning smell came up. Checked the tranny fluid and it was darkish like usual but smelt burnt. Turned it off and started it back up and the slipping disappeared.... It’s been two days since and I’m still driving it but now the transmission has acted up two times.. No slipping but it did one random downshift out of no where but stopped it almost as fast as it happened and it did this weird thing where I was going up hill at around 60ish, the rpms fluctuated about 300-400 rpms for about 10-15 seconds. Also, a new code came up besides the po700. It’s po876 for the pressure switch. This code came up after I got home from my buddies and parked it.

I know it’s a long and drawn out story that probably doesn’t make a lot of sense but I figured I would put everything in here. But what I’m wondering is can all these problems be cause by the transmission fluid being dark and burnt not providing the transmission the proper pressure and lubrication or could it be a electrical issue then I’m not finding??? I’m not going to lie, I’m scared to drive the truck to far because i don’t want to cause any damage to the tranny if none has been done already plus I don’t have the money for a rebuild...

 

Yes, 545RFE. So P0700 is just a general trans fault. It may not come up with a run of the mill scanner but there is almost ALWAYS another accompanying specific code that goes with it (which you have now). Assuming the fluid is at proper level, it will require diagnostic testing most likely beyond your capability to perform, though you can inspect the external wiring to ensure there isn't a break in the harness. You might luck out on this one because that particular code isn't the usual kiss of death (which are P0735, P0734).