Welcome to the site.
You may have an internal problem with the clutches.

PS: Looks like chryslerforum.com was no help either huh?

 

Thanks 1994 Sport, I had the transmission fluid and filter changed and i changed all 3 sensors on the transmission. Still giving me P0734 and P0792 so I took it to a transmission shop for diagnosis and they found electrical noise interference induced on the Transfer shaft speed sensor wiring in the form of random spikes on his readout. he had the van running and stopped in neutral while he was checking his readout and he observed a spike on that sensor. I have replaced plugs, wires and the alternator with no help. it rained today and now the trouble codes will come up in a few blocks. coincidence or grounding wires? I may have to take it into the dealer in hopes of finding out for sure. Both transmission shops believe that it is electrical and not internal.

P.S. I have not received a response from Chryslerforum.com so I think i stumped them

 

Hardwiring the tranfer shaft speed sensor circuits directly from the sensor to the controller is an option that a former Chrysler technical assistants center master consultant would offer. :thumb:

This will get the circuits away from the rest of the harness in an attempt to stop the interference.

 

Sorry to butt in but I'm looking for a solution for my 2010 T&C. Computer put out a P0750 "shift solenoid a " malfunction. I have the same issues as you. Trans goes into limp mode. If I restart the car it will go back to running normal and then something trips it back into limp mode. I can't find much info on the net and Haynes manual is no good either.



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Richie67; I do not think we are have the same nor similar problems. Your code points to a specific solenoid and that solenoid needs to be tested for possible replacement. the test and replacement are not too complicated if you are moderately mechanically inclined. Here is a link to a test process: http://easyautodiagnostics.com/chrysler/3.3L-3.8L/transmission-code-p0750-test-1
this is for a 4 speed transmission but if you have the 6 speed this link should give the info to check your solenoid: https://www.atsg.us/atsg/skin/frontend/default/atsg/corrections/09R62TE.pdf
Now if the solenoid check or replacement does not fix your problem then we may have similar problems as we have external signals interfering with our transmission signals. Good luck
P.S. If you are not comfortable with the above process then you should take it to a transmission shop for evaluation of the solenoid and the possible replacement of the solenoid switch pack.

 

1994sport; Thanks for the info, i have some shielded 2 strand wire that was left over from my work that will do fine if bypass surgery is needed. Block all outside interference
I need to look into the source of the interference in case it is a harness grounding or arching issue.

 

Update to my ordeal: I change the alternator and cleaned all the ground connections to the transmission and the body. I pulled the fuse box and took it apart(dirty connections were the culprit from a another forum) and pulled the PCM to look for obvious problems, all were clean and no noticeable problems. I took the van to the dealer and they hooked it up to a tool that simulates a working transmission to check the TCM/PCM and wiring harness. They said they shook down the harness during testing but the test passed, so it now points to the transmission and a tear down is the next step. They quoted me a price or $4,900 for a rebuilt replacement. I took my van to a transmission guy I trust and he completely rebuilt the transmission. He found #3 and #4 friction plates burnt and wore out. I had the van back for a couple of hours and I get the same codes as I did before . However I now have a new issue, the gear shift indicator, intermittently, shows boxes around all the gear shift positions (P,R,N,D) with the van in Park if I shift to drive the indicator moves to just a box around the D, if I shift to neutral then all the positions have a box around them.
Two thoughts: 1) Would a gear shift lever failing cause my original problem? I know the indicator problem could be from a problem during the rebuild with the lever position sensor but could a faulty shifter cause the codes from the beginning?
2) Could I have a failing TCM/PCM and it is just not faulting itself?
any thoughts or ideas will be greatly appreciated.
P.S. I have not run a separate shielded wire for that sensor yet, maybe that is the answer to the orginal problem and I am chasing a new one with the shift indicator?!?!

 

If anyone has the PCM wiring diagram for this 2010 Town and Country 3.8 Touring, that would be a great help

 

new wire run made no difference to my problem. Used working PCM/ECU on the way.

 

Interesting update: I replaced the battery and now I no longer have the check engine light illuminating nor is the van going into limp mode. I checked for codes and I still have (even after resetting the codes, they come back after a couple of miles) the codes P0734 pb and P0792 pb.

 

Your story is very similar to mine. Coming home from church one Sunday afternoon, the van went into 'limp mode.' Towed van to the dealership and was told 'need a new transmission.' Reset the code with a $70 Autozone code reader and drove it to my trusted mechanic - he replaced the solenoid pack and all the seals. The van still coded (P0733, P0734, and P0792). Carried it back to my mechanic and he disassembled the transmission (alongside a friend who owned a transmission shop). Everything was mic'd and measured and found within tolerance. Actually, he told me the transmission looked 'like new' inside. Transmission was re-assembled and re-installed in the van. The van still coded (P0733, P0734, and P0792).

So I called Chrysler and asked for an authorization for warranty repair. As the original owner, who religiously carried the van to the dealership for repairs, I felt entitled for some help. Especially in light of Chrysler's Lifetime Powertrain Warranty. Unfortunately, I bought the van in February of 2007. The Chrysler Lifetime Powertrain Warranty only applies to vehicles purchased on or after July 26, 2007. The customer service DID NOT authorize a warranty repair, but DID offer a 10% discount on parts. I did some quick math and determined the cost of repair exceeded the KBB value of the van. No thanks.

We still drive the van. When it codes, we pull over, plug in the Autozone code reader, and re-set the computer. I am not suggesting or recommending that anyone do this. But in my case, it beats paying $3,000+ for a new transmission.

I, like you, think the root cause is electrical in nature. I read with interest your thread as my next course of action was replacing the TCM. But now I am re-thinking that.

Thanks for posting.
Kevin

 

UPDATE: I took my T&C back to the dealer (after the transmission rebuild) to have them solve this mystery problem. They had it for 1.5 weeks and could find nothing but the wires I had bypassed during my troubleshooting. I had them rewire the sensors and they then suspected the TRS(Transmission Range Sensor) switch because of the instrument cluster indication. They asked me if the Compounder was replaced during the rebuild and I informed them that it was rebuilt but not replaced. They then pull the side cover off to look at the TRS and wiring. When the pulled the cover they said that they found chips in the pan and that it looked to be coming from the Compounder. They siad the the wiring looked ok and gave me an estimate for a Compounder inspection. I called my transmission mechanic(He rebuilt this trans) and he suggested that I bring it back to him because, "you hired me to do the rebuild and I should complete the work". That kind of integrity is rare nowadays, but I digress. My trans mechanic pulled the pans and could find no evidence of chips or fuzz. He proceeded to pull the tranny and go through it to ensure no contamination existed. He then pulled the Compounder out and apart and it looked like new. He mic'd out all the components and checked for warpage but the compounder was perfect. He had another rebuild kit in his shop and he rebuilt the compounder for a second time, just to be sure. He put it back together and replaced the TRS while re-assemling it, to fix the boxes around the trans position indication on the instrument cluster. (the indication problem started after the transmission rebuild, so my trans mech said he would replace that part antway as he did not catch that problem when he test drove it after the rebuild) When he went to test drive the van, the boxes around the indicators were still there. A little frustrated he went back through what he did on the original rebuild and he noted that he had replaced the solendoid body as a possible cause for the transmission codes(P0734 & P0792) I had been getting. Since all the signals from the TRS go throught the solenoid body connector he put a new solenoid body on my transmission and this fixed the indication issue. he then test drove the van and the P0734 & P0792 codes did not reappear. He drove the van for 10-15 mile with no problems (these codes would set within 5 miles everytime before). I picked the van up on Christmas Eve and it has been working great for the last week. So it looks like the P0734 & P0792 codes were corrected by the replacement of the TRS. As unlikely as that sounds, it is the only part, that was changed, which caused a change in the trouble codes.
If the TRS was the problem then I wonder how many remanufactured transmission were replaced for this simular issue, as a remanufactured unit would have a new TRS installed?
$4000.00 fix for a $30.00 part?
I am just happy that my T&C is back on the road and I will update should this problem rear it's ugly head again
Kwinters: something to look at, I believe you could change this at home and the part is inexpensive so no harm no foul if it doen't help

 

UPDATE: I took my T&C back to the dealer (after the transmission rebuild) to have them solve this mystery problem. They had it for 1.5 weeks and could find nothing but the wires I had bypassed during my troubleshooting. I had them rewire the sensors and they then suspected the TRS(Transmission Range Sensor) switch because of the instrument cluster indication. They asked me if the Compounder was replaced during the rebuild and I informed them that it was rebuilt but not replaced. They then pull the side cover off to look at the TRS and wiring. When the pulled the cover they said that they found chips in the pan and that it looked to be coming from the Compounder. They siad the the wiring looked ok and gave me an estimate for a Compounder inspection. I called my transmission mechanic(He rebuilt this trans) and he suggested that I bring it back to him because, "you hired me to do the rebuild and I should complete the work". That kind of integrity is rare nowadays, but I digress. My trans mechanic pulled the pans and could find no evidence of chips or fuzz. He proceeded to pull the tranny and go through it to ensure no contamination existed. He then pulled the Compounder out and apart and it looked like new. He mic'd out all the components and checked for warpage but the compounder was perfect. He had another rebuild kit in his shop and he rebuilt the compounder for a second time, just to be sure. He put it back together and replaced the TRS while re-assemling it, to fix the boxes around the trans position indication on the instrument cluster. (the indication problem started after the transmission rebuild, so my trans mech said he would replace that part antway as he did not catch that problem when he test drove it after the rebuild) When he went to test drive the van, the boxes around the indicators were still there. A little frustrated he went back through what he did on the original rebuild and he noted that he had replaced the solendoid body as a possible cause for the transmission codes(P0734 & P0792) I had been getting. Since all the signals from the TRS go throught the solenoid body connector he put a new solenoid body on my transmission and this fixed the indication issue. he then test drove the van and the P0734 & P0792 codes did not reappear. He drove the van for 10-15 mile with no problems (these codes would set within 5 miles everytime before). I picked the van up on Christmas Eve and it has been working great for the last week. So it looks like the P0734 & P0792 codes were corrected by the replacement of the TRS. As unlikely as that sounds, it is the only part, that was changed, which caused a change in the trouble codes.
If the TRS was the problem then I wonder how many remanufactured transmission were replaced for this simular issue, as a remanufactured unit would have a new TRS installed?
$4000.00 fix for a $30.00 part?
I am just happy that my T&C is back on the road and I will update should this problem rear it's ugly head again
Kwinters: something to look at, I believe you could change this at home and the part is inexpensive so no harm no foul if it doen't help

So what was the fix for this the connector?

 

I don't have your former issue but just wanted to say thank you for posting such an in-depth and very informative thread. Was a very interesting read.....

 

Same P codes

I have the same codes appear on my T&C with 75k on it. Tcodes P734 and P792. I am experience no issues with the van at the moment, but I am worried something will happen soon and my wife will be SOL as I travel quite a bit.
I am going to pull the negative wire tonight and see if they go away. I'll keep everyone updated.

Should I just bit the bullet and replace the transmission solenoid module as CirellaFamily has eluded to? Or do you think it was a compound of the tranny rebuild + the sensor replacement?

 

Hello a1freebu, The original solenoid pack on my transmission was most likely OK. The new solenoid pack was bad from stock and causing the "boxes around the letters" problem. I am confident that my issue all along was a bad TRS. The TRS is a $40 part but you have to pull the cover and that will drain some fluid. If you decide to change the TRS preemptively I would have your fluid flushed and filter changed. That being said, I have a question. Did you have a "check engine" light illuminated or did you just scan for codes and found these?
when my transmission was rebuilt, the #3 and #4 friction plates were worn and had definite signs of slippage/burning (which I believe was caused by the electrical issue with the TRS) but they were not so bad as to cause a need for a rebuild. In other words if I had replaced the TRS first, before the rebuild, I would have most likely gotten many more miles before a rebuild would have been necessary.
Good luck and I hope you solve your issue as cost effective as possible.

P.S. It has been almost 1 year since this issue and I have put almost 15k miles on my van with no problems to report ???

 

Cirella,
Your posts Have been very helpful. The check engine light just illuminated about a week ago. I do not have any symptoms such as limp mode or driving issues. I am hoping to find one of those TRS assemblies today and replace. If I can't I will have to do sometime in the following two weeks since I am going away on a work trip

 

Update : Called Chrysler they said I was 6 months out of warranty and they would not cover or discount any parts. Transmissions issues seem onto be a typical problem with Chrysler's I will never buy one again. Especially since I did not get any support from them. I had an independent shop rebuild it for 3000 bucks, problem is fixed, no more fault codes, now looking to sell the van

 

This whole tranny worries me with the way it shifts. It certainly Should last longer than 100000 miles.

 

So after the rebuild the tranny worked great. Then as week later the transmission started making a a high pitch whining noise when only decelerating from 25 mph to 10 mph. I took it back to the tranny shop where they noticed the same issue. He tore it all down and rebuilt it as it was still under warranty without any hassle. Which I thought was great. Well I got it back and after driving it three miles out of their shop the engine light came. Taking it in tonight to see what codes they pull.

 

Update:
The transmission shop pulled the codes and they were the exact same codes I originally came in with P0734 and P0792 . I left the car with them, they reflashed the computer, but the codes came back on as I pulled away from the shop.
I took it back to the shop they, replaced the TRS, drove it around, light came on 60 miles later. The shop pulled the codes and they were the same codes. Frustrated I left and asked them to do research as I was not wanting to come back. I took it back to the shop, who did further research and found someone in Texas with the same problem as I. Through what he had found, they replaced a check ball valve that was in one of the pistons that is not a standard rebuild part. They took the old ball valve and pressured tested and found it was leaking. So far after 200 miles, the light has not come back on.

I give it to the shop they provided me with a rental car and were relentless on fixing the problem.

 

whats the name of the shop?

i would love to know which shop was working on this as i have the exact same problem with mine, down to the tee the same problem to find out what they did, can you post the trans shop name and location so i can call them?>

 

I've had the same codes (P0792 and P0734) with my newly acquired Routan. Alternator ripple was fine, all the solenoids and wires check out, and the speed sensors were replaced with no change. Research pointed me toward the low clutch drum sealing-ring lands in the compounder, so I pulled it out. It actually turned out to be a damaged seal on the low clutch apply piston. I made a video if anyone wants to see the insides.

 

Great video. Thanks for sharing. All these resources weren't around back when I had all my 62TE issues. First it started going into limp mode and I had to get a new transmission harness connector spliced in.
Then several years later, my compounder died and I had my transmission rebuilt. Within a year later the solenoid pack died and they replaced that under warranty. The other thing to note is I had a very intermittent no-start condition later. It would just click when I tried to start it. That was fixed by opening up the 62TE again to replace the Transmission Range Sensor. You may want to watch out for that too. You could start it immediately by shifting into Neutral.

 

Hello all.
Chiming in to hopefully help out someone down the line.

Surprised no one has mentioned the transmission firmware update.
Updates timings for all shifts and several harsh shifts (I only ever use ECO mode on highway after I am in a higher gear because of it) didn't know there was this update.
Seems it was never done on this vehicle. Going to get it done tomorrow. Likely played a part in this transmissions early demise having made harder than it should shifts at all points in it's lifetime.

2011 T&C Limited nearly mint condition, got it for $7k usd last fall.
Van only has 45k miles.
Changed fluid and filter at 38k miles a month after purchase (with half bottle lucas because of those hard shifts mentioned from the firmware update).
Always had a jolt into D when it was ran nearby like to the post office. Then starting it again and going into D when it was 'warm' would do it. When hot or cold it didn't do this. But it showed something out of the ideal was at play from the beginning.

This week when 5 hrs from home got CE light,
Bluedriver shows codes:
P0734 (gear 4 incorrect ratio)
P0792 (compounder speed ratio error)

Drove carefully and found no issues, seemed to shift to every gear except 4th which didn't make much of a problem.
Shifting is pretty smooth.
Drove all the way home at 71mph. Almost home and stepped on it up to 93mph to see what might happen. No issues.

Decided to try replacing the input shaft speed sensor and the code went away on startup. Drove it through the range and went through all gears pretty smooth (including 4th).
Code came back on shortly after, maybe skipping 4th gear when the code is on but not certain of that.

There is also a sound I haven't heard before this happened, when putting ear above the transmission (can't hear it as much below it)
It is the same sound I heard on old van when a relay died - it is the same kind of 'click pop' like the bad relay, in park, about every 10 seconds - regardless of RPM.

Do I go for a rebuild or not, is the question. Mainly given there is no real mechanical problem showing itself yet.
But the cost of the vehicle and it's real use value given fully loaded and everything else is great, makes it easy to justify.
Was planning to drive across the country next month.

Rebuild notes from research:
-replace the torque converter with rebuilt one (the clutch material inside wears out with age just like the clutches)
-replace the lower drum with updated one with notches in rings
-closely inspect transmission range sensor
-replace the solenoid pack
-replace the TCC solenoid
-replace the transducer (sensor?)
-replace the coolant hoses
-clean everything inside
-measure the 3 check ball valves for any loss of size and replace if they aren't at full spec
-flush the coolant lines/radiator
-replace the pan with Dorman drain plug pan for easier future filter changes/ use a gasket ONLY if you don't want a mess doing future filter changes
-replace the piston in the lower drum with the new one (added this line after rebuild - see post below)


Edit:
1st drive since the day this happened... on a 5 hour errand trip there were 2 times where it seemed a slight hesitation in shift around 3-4-5. Checked bluedriver again and now also code PO733 (3rd gear ratio) pending code. Then after half of the trip reverse definitely shows its problems.. the lever shifts fine but once you remove the brake and the vehicle starts moving it really hesitates/slips as it starts moving.
The commonly breaking old model drum wear out. I estimate 10 or less reverse's before it won't for good.
So.. a rebuild it is.

 

To provide an update of accomplishment, it was the seal on the low drum piston just like pvfjr found. Causing the fluid pressure behind it to pass by, causing the system to increase the line pressure and make for problems in moving the clutches into place properly. Everything else was in good looking condition. However the fluid was loaded with aluminum particles. The mechanic said since nothing else looked worn out, it could likely have been from inside the torque converter.

Seems they (mopar) have actually updated this part too, not just the lower drum/rings, the new piston seal is brown and is nearly double the thickness as the old seal. Did not encounter anyone mentioning this is any of the youtube videos research marathon.

To conclude, this likely happened from being 9 years old and a weak part installed from the factory in these vehicles from the beginning. As an added note the mechanic said to never use lucas or any atf additives, said they soften the seals and cause things like this to happen sooner (mainly on already weak parts). Said only use them if your near the end of the life of your vehicle and something is failing in the trans and you want to squeeze a bit more life out of it before it fails and becomes a scrap or rebuild.

May all your transmissions be healthy and happy 🧙‍♂️

 

I also wanted to thank you for always following through with a thorough description of what you did. I love my T&C and want her to live forever.

 

..now I have the same problem can you tell me if you have fixed yours and what was the issue please ?