48re, no forward gear, only reverse

[cliff Teel]

I have a dodge 2500 4x4 Cummins with a 48re. I put in drive one day and nothing. I thought maybe I knocked the transfer case out of gear. But no. I lost drive. It will back up. But I was facing down hill when it first happened. I started rolling, I put it down in low, switched it to tow, , nothing. Then all the sudden, it slammed into gear. I went about 30 miles, stopped at a red light, and took off no problem. it shifted great. like nothing was wrong . When I got to a friend's shop, backed up to the doors, then went to take off, nothing and nothing ever since. The first time I pulled codes it said no signal to the torque converter clutch and transmission no signal. Now it says low transmission fluid pressure. I've checked the fluid. And it doesn't smell or look burned. Can this be repaired without pulling the transmission? And it has been rebuilt before I bought it, I just put an engine in it and it has a much bigger torque converter and evidence shown where it had been done. Does anyone have any idea what I can do?

 

[Timd32]

Some simple stuff. I would always go back over stuff you actually touched last. Connectors and grounds and the sort.

Without dropping the pan.....

External to the trans you can try to swap the Trans Control Relay, TCR with one of the other ones if there is a spare. I think it's in the Power Distribution Center.

Have you checked the 8pin connector on the trans? Make sure its plugged in and the sort. Make sure you have power and can read some of the feedback from the wiring diagram.

I'm sure you remember to check your fluid level in Neutral not park.

Did you hook up and adjust your TV cable that could cause damage to some internals if its left unhooked.

Internal to the trans the Gov Pressure Solenoid controls the 1, 2, 3 stuff could be something with that, but based on those codes check the controls to the Trans first.

Then you can dig into checking pressures and the sort. I think the Gov pressure should go high with the 8pin unplugged in drive. But you need a decent gauge and the sort to do those checks after you confirm some other.

Hope some of this is not way off base. Someone else might correct any mistakes above as well, or notice something simple here.

 

[cliff Teel]

Yessir, this is all good information, I've been working on vehicles my whole life, even worked logging, some of our log skidders had 5.9 cummins, but they were warranty, so I never really done much wrenching on them. Really didn't have to. This is all new to me, so I'm definitely learning here, I do know enough that I'm missing something and not to do too much not knowing what I'm doing, in fear of costing myself more. My budget on this truck is gone, so I'm sure something you've provided will be of help, I've checked all you've mentioned. But I can't find anything or anyone around here that can tell me which wires to the transmission is supposed to be hot when in gear or drive. That's what I was thinking would tell me for sure if I am getting any signal. Thank you again. If anything else u or someone can think of, I'm paying attention. I just believe from the way it behaved before I lost drive, I feel I'm missing the gremlin that is hiding from me.
And laughing.

 

[Ozymandias]

Download the factory service manual, its out there as a pdf for free. That will guide you through the trouble shooting.
There in is written what to check if there are no forward gears anymore.

 

[Timd32]

Yeah the troubleshooting tree might be your best bet......


Here is a stab at the connector pin out. I'm sure Google will have some fancy color charts for yours.

Colors and controls could vary. This is my 96 I know the control boxes vary at some point so again this is truck specific at times.

Pin 1 +12 "red" (from the TCR relay) used for the Solenoid coils.

Pin 2 +5v "orange" (from PCM 31)

Pin 3 sensor ground "blk/lt blue" (from PCM 4)

Pin 4 governor pressure "light grn/wht" (to PCM 29)

Pin 5 governor solenoid "violet/wht" (from PCM 8)

Pin 6 Overdrive Solenoid "brown" (from PCM 21)

Pin 7 TCC Solenoid "Org/Blk" (from PCM 11)

Pin 8 Trans Temp "Violet" (to PCM 1)

 

[cliff Teel]

Got an solenoid upgrade kit for 48re 4x4 dodge cummins, as u see since I last posted, installed the whole kit, new fluid and filter, put in neutral check fluid, tried to put in drive, no forward gears. It's got to be in the wires somewhere. Any one with experience will help, still have reverse. I still think it could be a bad wire or connection, cause it did go into gear and shifted fine til I stopped and put it in park, when I started the truck put it in drive. Nothing, but reverse. Don't want to rebuild it again if there is no need. I know there is someone that knows these transmission and shed some light and shorten the chase, just need some direction please.

 

[Timd32]

You should cross post on mopar1973man.com

They have 3 or 4 folks who might be of assistance.

Sucks it was not something simple for you like the trans relay or the power to the 8pin.

 

[cliff Teel]

Thank you for the address, and it's not any of those, just installed an upgrade kit. And showing low voltage to the transmission now so, I'm leaning towards a broken wire in the harness. It did get pulled pretty hard. I appreciate the help

 

[cerberusiam]

Pull the trans and go thru it. If you lost all forward gears but have reverse the forward clutch is blown. The codes could be a bad VB harness, garbage in the sensors, or a bad PCM\ECM depending on the year of truck. There is nothing in the electronics that will stop the trans from have reverse and at least 1 forward gear, if it quits moving one way or another it is an internal mechanical failure. The only place trans pressure is read is a control circuit not an apply circuit and that could be harness or garbage in the sensor.

 

[cliff Teel]

Thanks guys for all the help, this really is a big learning experience for me on this dodge. Had to walk away from it a few days. Did another check the scan showing low voltage to transmission and low pressure. Thinking of a new plug, found out from a friend who runs a parts store they sell alot of them, transmission shops r replacing these alot. I've checked the wires and plug, couldn't see anything, but he told me the wire will break inside the insulation. They will get pulled and stretched sometimes when they pull the transmission and the shops are buying them alot.
So, gonna pull myself up and get it on my mind, this don't do it, it's getting yanked out and going to monster transmission, they have the best deal on rebuilding one with all the upgraded parts, which I've already paid for accept the internals. If I had a coach I'd attempt it myself, as much time as I have with it. But, maybe there is a hail Mary, a friend of mine found a broke ground wire on his truck not long ago, couldn't get it to run sometimes. Or it would just die. He was about to consider arson. Lol, come to find out by accident, ground wire. It can be the simplest thing, right in front of us

 

[Timd32]

Cerberusiam is the one of the best out there on these things, rarely is he off.

I somehow thought you had Manual control at some point, follow his post above.

 

[Prairie Dog]

Did you see what all the possible codes indicate in TimD's post?
As Cerb suggested, there's NOTHING in the harness that will keep it from going in gear. You could disconnect or short any of those signals and it would still go in gear. I sure wond't cut off a plug that has no impact on your issue but it's up to you.
Good luck!

 

[cliff Teel]

Cerberusiam is the one of the best out there on these things, rarely is he off.

I somehow thought you had Manual control at some point, follow his post above.

I have been preparing myself for it in the back of my mind. Thank you for your help

 

[cliff Teel]

Did you see what all the possible codes indicate in TimD's post?
As Cerb suggested, there's NOTHING in the harness that will keep it from going in gear. You could disconnect or short any of those signals and it would still go in gear. I sure wond't cut off a plug that has no impact on your issue but it's up to you.
Good luck!

Did you see what all the possible codes indicate in TimD's post?
As Cerb suggested, there's NOTHING in the harness that will keep it from going in gear. You could disconnect or short any of those signals and it would still go in gear. I sure wond't cut off a plug that has no impact on your issue but it's up to you.
Good luck!

The only thing that keeps that coming to an issue is that the first scan that was done is it had a code that was saying to cominication to transmission, and after trying to find what's really going its reading that there is low voltage to the transmission. Can anyone enlighten this issue. I never had this many wild mysteries at once. Thinking about medicating myself getting a little therapy on my old Harley and maybe come back with an epiphany. Unrealistic, but a man can hope. I have so many telling me they'll bet that's its electrical donf spent big money for nothing. But what y'all r telling, with a very good description, is telling me that this just will probably be the gremlin. But still, I'm very confused. Fluid not burnt, there was no evidence of a crime scene laying in the bottom of my pan, going into gear and shift perfect, (only once) and the scanner finding it telling us there is low voltage. I don't want to waist money, this transmission is not very old, but I've seen one quit backing it out of the shop for a test drive. I'll go back study, thanks

 

[DanThisGuy]

I have a dodge 2500 4x4 Cummins with a 48re. I put in drive one day and nothing. I thought maybe I knocked the transfer case out of gear. But no. I lost drive. It will back up. But I was facing down hill when it first happened. I started rolling, I put it down in low, switched it to tow, , nothing. Then all the sudden, it slammed into gear. I went about 30 miles, stopped at a red light, and took off no problem. it shifted great. like nothing was wrong . When I got to a friend's shop, backed up to the doors, then went to take off, nothing and nothing ever since. The first time I pulled codes it said no signal to the torque converter clutch and transmission no signal. Now it says low transmission fluid pressure. I've checked the fluid. And it doesn't smell or look burned. Can this be repaired without pulling the transmission? And it has been rebuilt before I bought it, I just put an engine in it and it has a much bigger torque converter and evidence shown where it had been done. Does anyone have any idea what I can do?

Hey I'm so curious where you've gotten since. My truck did basically the same thing it drove fine for two weeks (after fixing torque converter lock-up by replacing the O/D & TC lock solenoid) it worked fine then one day coming home I get in the drive way then later try to leave and reverse works like a charm but nothing in the forward gears