Transmission Issue after it was replaced .... HELP

[SavannahRam]

Hey fellas. 2007 Ram 1500 5.7

Before replacing tranny: Mysterious one day the tranny filter 'broke' off while I was driving. All of the sudden it would barely move at all. After limping home we and the mechanic dropped the pan and found this out. We placed and redealed and it was good to go. We pretty much agreed that something that tramatic put a time limit on the tranny. Im an independant distributor and put a ton of miles on it anyway. So, from that point foward every now and then Id start it and it wouldnt have alot of power in first gear. it wouldnt roll foward like it should and would rev real high until getting past first. Eventually it would hard shift now and then as well. Eventually the tranny temp light started coming on and one day it failed. I took it to the shop and they of course said the tranny was done and that I had a glod on my treanny cooler and radiator.

Got it replaced with a used tranny (I aint rich) I just got it back about a week ago. When I first for it back I noticed on the Dash all of the gears are selected until I put in into gear. Ive read a few threads where that is the case and the truck wouldnt start ... well mine started no problem and drove fine. It downshirts hard into first from highspeed sometimes, but other than that drove great.

Then all of the sudden the check engine light came on today and I had no power in first like before the replacement ... and all gears stay selected on the dash no matter if its in gear or not. My buddy took it to get the code from the light and it was p0846
Transmission Fluid Pressure Sensor/Switch "B" Circuit Range/Performance
it says replace shift silenoid but I wanted to post about it and get opinions cos of what the dash gear selector is doing .... thanks for any help.

 

[MADDOG]

Yup...that P0846 code means that either the sensor has gone bad or the solenoid has gone bad and you don't have proper operating pressures in the transmission.

I think the gear selector issue, which was present before the code, isn't related to the solenoid or sensor failure. It has another root cause and I suspect it's electronic, maybe in the Body Control Module.

 

[SavannahRam]

Thanks for replying.....

Yeah the selector issue is def. electronic from what Ive read online, but its hard to find anything about that particular issue with the car still driving. Most everything Ive found the truck will not start when this issues occurs. Ive read it may be a battery issue: dead cells or bad connections .... one of my terminals is mysterious awful looking after not being driven for two months. Im\ll eventually figure that out.

Tranny ...... Well I drove her today because I really didnt have a choice. My business depends on it and I tow a trailer. She drove like a dream for about half the day, and then all of the sudden is started doing it again, same symptoms but now there is another issue!!! As I mentioned before all of this the tranny temp light had been coming on, and I always figured it was just because she was about to kick the bucket, but when it finally happened I was told I had a clogged transmission cooler. I had everything flushed when I had the work done on it and the mechanic said everything was good ..... but this afternoon after getting home and resting the truck for a while I drove it and the temp light came on. I cut it off and sat for a minute and then drove and it eventually came on again. Obviously I feel like an ass for not just replacing it, so Im going to do that now -- but it seemed kinda odd for it to not get hot all day long and then get hot on a 5 minutes drive down the street. I dunno ....

And what 'sensor' are you referring too? Im still learning about transmissions...

 

[SavannahRam]

Yup...that P0846 code means that either the sensor has gone bad or the solenoid has gone bad and you don't have proper operating pressures in the transmission.

I think the gear selector issue, which was present before the code, isn't related to the solenoid or sensor failure. It has another root cause and I suspect it's electronic, maybe in the Body Control Module.

Hey I quoted you because you were the only one who responded back in August haha, but I need to revive this thread as Im still having the Issue! I pretty much chalked the Check Engine light and code to a bad Shift solenoid, but im convinced this cant be the issue! This truck has pretty much sat in my yard since August because I needed to save up the money to get the replacement tranny put in (i got this one used and had a 6 month war and doing that was cheaper than getting the part and paying to have that put in) but about two weeks ago my mechanic needed a truck to move some **** around his yard so I let him barrow it figuring **** it Im replacing it anyway .... well after driving it about 30 minutes it was fine. Shifting so smooth you'd have to watch the gauges to even tell! He called me and we were both dumb founded .... check engine light still on, and the selector issue has a new wrinkle! When the Truck isnt driving correctly all gears are selected no matter what - when its driving without any issues all gears are selected until you take it out of park. Once in gear only that gear is selected. I drove it for a day or two and even the check engine light went off and like I said - driving like a dream. Well, a few days ago all of the sudden it regressed. Crank it, all gears are selected no matter what, and it has no power ...... checked fluid and it seemed low, so I added a quart .... turned off and back on and it was fine. Now its doing this a few times a day ... it'll all of the sudden no drive right, but if I turn it off and back on a few times it'll be fine.

After doing a bit of research I found this thread - https://forums.vwvortex.com/showthread.php?4813252-ALL-Gear-Shift-Lights-On-at-One-Time-on-Dash - obviously that's a VW forum but Im pretty sure what's being talked about is universal and this problem is basically the same as mine .... in that thread what my truck is doing is being called 'Limp Mode', where it basically drives in 3rd gear because the TCM is telling it too, the TCM is also being pointed too by some as the reason why all hears are selected. Ive also read in that thread it could be a break light switch (really?) causing the issue, or a bad battery.

Any insight? Opinion? Anyone else got 2 cents to add?

Im going to take it to a tranny shop to get check but im pretty sure they are just going to tell me the solenoid is bad but It cant be! Ive been told once they go, they go - but my truck will drive like a brand new truck 95% of the day!

thanks in advance for any response!