Aisin hard-shift

[dsmith17]

Got truck back yesterday from dealer and all seems to be fixed.
The cause was a failed transmission range sensor which they replaced.
Appreciate all the feedback. -Dave

 

[dsmith17]

Daggum, after three weeks from having transmission range sensor replaced by dealer and trouble free driving I had the same problem recur a few days ago.

Backing out of driveway and shifting from R to D resulted in a very hard shift, limp mode (yellow lights for P, R, N, D) and CEL. Shutting truck off and restarting cleared it.

But next day I couldn't clear limp mode even after 5-6 repeated restarts (drove home in limp mode). Was just leaving a parking space (that I was backed into so going forward was the plan) and just shifted from P to D. Once shift indicator landed on D all lights went "yellow" and hard shift when put back in park.

QUESTION: Is the problem me (how I'm shifting) or something with truck?

I guess it's possible that I had NOT come to a COMPLETE stop (when backing out of driveway) before shifting from R to D. Are these Aisin trucks THAT FRAGILE?!!

 

[mpaulson]

I had a similar experience. It turned out to be one of the pins in the big electrical plug that is under the drivers side floor board that has about 50+ wires in it. One wire that was for the transmission had a pin that the retaining tabs that hold the pin in place within the plug were broke and this allowed the one wire to back out at random and cause a loss of communication. Trans engineer who is on this site recommended checking this and I told my dealer this, they checked and found it. Two other dealers that I stopped at while I was on holidays wouldn't listed to me and and didn't check it, I could tell because the Northwest Territories mud was still caked on the plug after being at the dealers. My dealer found it because when it happened I kept it in drive, drove it to the dealer, left the truck running and in drive with the parking brake on and they came out and plugged in there computer and could see that there was an open circuit that was not supposed to be open while in drive so they now could trace that wire through the system and trans engineer was right!. Maybe talk to your dealer and see if they will do this if you drive it in next time this happens.
Or open the plug that's under the drivers side floor board and look for a pin that is not sticking out the same height as the rest, gently push on the pins and see if any move into the plug. They moved the faulty pin set to an unused pin spot within the plug and three years since I have not had this reocure.

 

[dsmith17]

Thanks for that reply!

Unfortunately, the problem is not "full time" so whether dealer can replicate it or not is uncertain. Dropped truck off today and I was assured by svc advisor that their most experienced heavy-line diesel mechanic will work on it Tuesday (with Chrysler also in the loop).

I did share your thoughts with them about wiring harness. He took down notes so I'm hopeful they will actually get to the bottom of it.

Many thanks!
-Dave

 

[Newsa]

Well the TCM "Limp Mode" issue occurred again today while driving slowly in a parking lot. All "letters" (P-R-N-D) went to yellow and shifting into P (park) was very rough. Shutting down and restarting cleared it (but of course had the CEL). Then it happened again in my parking space but this time shutting down and restarting did not clear the "Limp Mode" (i.e., all letters remained yellow and shifting into D or R was very rough). Finally, a third shutdown-restart attempt cleared it and all letters were white and when shifted from P to R the shift was normal and smooth and the R was red in color; and when shifted from R to N and then D those letters were white (all normal).

I have an appointment at dealer service department to hopefully have this fixed. Taking the boys camping Friday so expect it will be a miracle if I get the truck back in order to tow the travel trailer. :/

Oh...I found a dead squirrel in the bottom part of my radiator fan shroud. That was a joy to remove (God help me the smell was bad). Maybe this critter got to some wiring? Or maybe just bad luck?

View attachment 99486
View attachment 99487

What color are the R N D L letters normally?

 

[dsmith17]

White (except R which is red when in that gear).

 

[dsmith17]

Bad terminal

I had a similar experience. It turned out to be one of the pins in the big electrical plug that is under the drivers side floor board that has about 50+ wires in it. One wire that was for the transmission had a pin that the retaining tabs that hold the pin in place within the plug were broke and this allowed the one wire to back out at random and cause a loss of communication. Trans engineer who is on this site recommended checking this and I told my dealer this, they checked and found it.

Got truck back from dealer yesterday. Problem turned out to be a bad terminal in I-255 inline connector... looked like it had been crushed during installation (see attached photos). TransEngineer on another forum pointed me in this direction and I relayed that info to dealer. Thankful for these Cummins forums and folks who are willing to share their knowledge! These trucks are complicated! Many thanks!! -Dave

 

[Regcabguy]

One should ALWAYS be stopped when changing gears. I always pop my trans in neutral before going F to R or R to F. Learned from my built DDT trans.

That's what I was told to do with my DTT.

 

[SnoKing]

That's what I was told to do with my DTT.

Bill chewed me out once in his parking lot for shifting while the truck was still rolling backwards! SnoKing

 

[Regcabguy]

Bill chewed me out once in his parking lot for shifting while the truck was still rolling backwards! SnoKing

My dad rammed that down my throat. Also set the brake and let the truck roll forward/back before shifting into park.

 

[dsmith17]

3rd Trans Limp Mode -- 2 trips to dealer haven't fixed this

I'm beginning to have some big concerns about my 2-month old 2017 3500 Cummins/Aisin.

I've been to the dealer TWICE and still having this recurring problem. When it occurs, it usually results from backing out of driveway and shifting from R to D -- very hard shift, limp mode (yellow lights for P, R, N, D) and CEL. Shutting truck off and restarting usually clears it but not always.

NOTE: And I am very mindful to NOT be rolling when shifting (e.g., from R to D, etc.).

I've read a bunch of threads where folks have electrical problems that the dealer sometimes just cannot figure out. Then the dealer has to buy back the truck (lemon). What the heck?

I purposefully avoided getting a 2017 Ford Power Stroke since it was the first generation of a new design so as to avoid problems like this. The 2017 Ram is like the fourth generation. Shouldn't be having these types of problems. And sure as heck ought to be able to resolve them without the customer having to make multiple trips back to dealer for the same problem.

QUESTION: Is it a bad truck or a bad service department? Or both? Any advice is appreciated. Feeling very frustrated.

Many thanks! -Dave

 

[jhenderson]

As you stated earlier, these trucks are complicated. The right tech will find your problem. Your problem will be to find the right tech.

 

[mpaulson]

The problem is is that it has to be doing the issue that triggers it while at the dealership with there computer connected to pinpoint the cause quite often. That was the case with mine. I got lucky and it did it while I was in town and drove it there, left it in gear with the parking brake on and they came out and plugged in to find the "open circuit" that was the source of the problem.
The truck is awsome, but one little wire out of thousands had a connection problem providing a few months of grief to catch it at the right time for them to trace it.

 

[Ram4Sam]

I'm beginning to have some big concerns about my 2-month old 2017 3500 Cummins/Aisin.

I've been to the dealer TWICE and still having this recurring problem. When it occurs, it usually results from backing out of driveway and shifting from R to D -- very hard shift, limp mode (yellow lights for P, R, N, D) and CEL. Shutting truck off and restarting usually clears it but not always.

NOTE: And I am very mindful to NOT be rolling when shifting (e.g., from R to D, etc.).

I've read a bunch of threads where folks have electrical problems that the dealer sometimes just cannot figure out. Then the dealer has to buy back the truck (lemon). What the heck?

I purposefully avoided getting a 2017 Ford Power Stroke since it was the first generation of a new design so as to avoid problems like this. The 2017 Ram is like the fourth generation. Shouldn't be having these types of problems. And sure as heck ought to be able to resolve them without the customer having to make multiple trips back to dealer for the same problem.

QUESTION: Is it a bad truck or a bad service department? Or both? Any advice is appreciated. Feeling very frustrated.

Many thanks! -Dave

I've been down this road, wasn't a lot of fun but it will solve the problem I would read up on the Texas lemon laws....just in case. Knowing you had squirrels, my money is that Rocky ate the wire harness somewhere.......If it is in your wheelhouse, I would crawl under the truck and check every inch of the wire harnesses you can get your hands on.

Sam

 

[dsmith17]

The problem is is that it has to be doing the issue that triggers it while at the dealership with there computer connected to pinpoint the cause quite often. That was the case with mine. I got lucky and it did it while I was in town and drove it there, left it in gear with the parking brake on and they came out and plugged in to find the "open circuit" that was the source of the problem.
The truck is awsome, but one little wire out of thousands had a connection problem providing a few months of grief to catch it at the right time for them to trace it.

Anyone know how fast the truck can be driven when transmission is in limp mode? Is it normal driving (except for the very rough shifting) up until a certain number of miles have been reached before the truck will be limited to only a very slow speed (like 5 MPH)?

Our dealer is about 40 minutes away so would need to be able to drive truck on highway in order to get it there in the "limp mode state" for them to plug in and troubleshoot.

 

[Bob4x4]

The limp mode is not mph limiting but gear selection.IIRC with the aisin there are 2 gears available plus reverse

 

[Newsa]

The limp mode is not mph limiting but gear selection.IIRC with the aisin there are 2 gears available plus reverse

How is limp mode activated with G56? Does it cut back the turbo boost?

 

[gsbrockman]

How is limp mode activated with G56? Does it cut back the turbo booat?

You are joking............right?

 

[Newsa]

You are joking............right?

I was sort of half joking. But i am interested in how limp mode works in my truck.

 

[Bob4x4]

We were talking about trans issues.Engines de rate power for some faults.The def issues are the only one I can think of that limits mph