2001 46RE, No 2-3 Shift

2001 Ram 1500 4X4. Issue just started today, without warning. I drove it to a buddies house and it ran fine. When I left 2 hours later, the transmission wouldn't shift from 2nd to 3rd.
Transmission was rebuilt 50,000 miles ago, and is ready for routine service, but I wouldn't think that's the problem.
My internet research leads me to believe the governor pressure solenoid and governor pressure sensor needs to be replaced. The service manual's diagnosis chart doesn't cover this specific issue.
Ideas?

My first thought is the front clutch piston seals....

I've read that solonoid pack can be troublesome, but I've never had any issues.

No mention of check engine lights, Mike, but disconnect your battery overnight and re-hook it up and see if the problem continues. The computer in these trucks is not overly useful for giving codes, so, start with the easy stuff................

The governor pressure switch gave a code on my 97 46RE, but we had to scan it to see the code.
The problem I had was when I dropped the pan there were lots of chunks of clutch/band lining laying on the bottom of the pan. Gene

Job security:

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and,

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I'm sure toyota, Hyundai, Kia, and Mitsubishi body/mechanical Tech fits in there somewhere, but you get my gyst.

No mention of having reverse - if you do and it is strong then likely you either have a stuck throttle pressure linkage or a bad pressure transducer. (A stuck TP plug could do it but not very common).

A technician would first check the throttle pressure cable at the transmission and make sure the return spring is there and functioning.
If it isn’t and the throttle cable was stuck you could have high pressure and a late shift. Check that first since we had issues with both the cable and that spring.

Put a 100 pound gauge on the governor port and take it for a ride.
If it’s not close to vehicle speed then I would replace both the solenoid and transducer.

The tap is at the junction of the main case to the overdrive unit - on the passenger side of the main case at three o’clock.

Hyundai/Kia engine tech. You will not run out of work for the foreseeable future and probably not in my lifetime.

My Diesel Dodge is doing that. It will shift cold once or twice at light throttle but after that it hangs in second. It will shift from second if I very quickly shift Neutral to Drive and then it does its thing correctly.

My transmission guy says it probably needs a pressure transducer but to change the solenoid too as they are both problematic.

Kevin

Most common deal with the gov psi transducer was coming up to a stop and the trans wouldn’t shift down to first.... pull it down manually and you’d have first.

Wouldn’t a stuck kickdown also effect the 1-2 shift? I’ve seen rocks lodged in by the lever.... some peoples luck

No codes (in self diagnostic test)
I'll disconnect the battery for a few hours
I DO have reverse, and I'll have to check first gear. It definitely downshifts manually to 1st, but I guess there's a chance I was starting out in second when selector was in D. I was PO'd and flustered limping home...

I don't have tools to pressure test, and definitely don't have the experience to dig very deep. The only transmission experience I have is dropping the pan and replacing the filter. I don't mind taking to a shop, just would rather fix it myself if the fix was within my comfort zone. I'll report back soon...

As said check the kickdown linkage. But I usually find if the 1-2 shift is still normal it usually is not the throttle pressure kickdown linkage. We did have problems on some years as I cant remember which years where we would replace the front drum and piston and seals with updated parts for a late or no 2-3 shift. And I found reverse usually would still work normal since it uses much higher pressure. And I also some some with no codes where the gov pressure sensor and solenoid fixed it as we did have a lot of problems with them. Couse we would watch the gov pressure on the scanner to see what it was doing. Good luck with it, Ron

As it turns out, the truck starts out in 2nd and only shifts to 1st manually. I know it's tough to diagnose when you get bad information. I apologize for that. Once I figured that out, I disconnected the battery for almost 2 hours; no change. TV cable seemed good and nothing jammed up in the linkage (a quick once-over). Rather than take guesses, throw parts at it, and waste more time on it, I took it to a trusted transmission shop. He called me very soon after I dropped it off and told me the transmission wasn't getting anything from the computer. So now it's at a different shop waiting to see whether it's a broken wire, or a bad ECU, or...? Thanks to all for your input. Once I get the final verdict, I'll chime in.

"told me the transmission wasn't getting anything from the computer. So now it's at a different shop waiting to see whether it's a broken wire, or a bad ECU, or...?"

That's a new one.

Only thing tied to the computer that I know of in mine would be the Vehicle speed sensor, rear wheel abs, brake switch, and throttle position sensor.

I'm going to put my money on vehicle speed sensor at this point.

I had this exact problem on a 2000 Durango. The module on the passenger side inner fender had to be replaced. I bought a rebuilt unit online from a place (don't remember the name) in Florida for about $200. Took 5 minutes to install.

Interesting.... so he wasn’t able to view trans data? Viewing gov psi via the scan tool of your choice would be beneficial

It is stuck n limp mode, got to finger out why. I would check simple things first like fuses and the relay, I have had customers sent to me with "bad trans needs rebuilt" diag by udder shops and it is simple stuff like that. Check every fuse related or not and swap the trans relay with one for the horn or starter or something and see if it starts working (or the starter quits working). There is probably a p0700 in the engine computer that just says something like trans problem but unless you go in the scanner under "transmission" you will not finger out what the code in the trans conputer actually says. The cheap autozone scanner will come up with the p0700 no matter what code is in the transmission section of the confuser.