My 2010 Town and Country 3.8 with 6 speed transmission, has a check engine light on with codes P0734 and P0792 also the Transmission went to limp mode. I reset the codes and they came back in about 5 miles of driving and it went into limp mode again. I had the Transmission fluid and filter changed and cleaned input and output shaft speed sensors. Same faults appeared after 3 to 5 miles. I changed the input shaft sensor. the same problem happens again but if i turn off the van and restart it, the check engine light is still on but the van shifts normal for another 3-5 miles or so. The problem seems electrical in nature and the mechanic that changed the fluid and filter said that the fluid looked not burnt but dirty and there was not a lot of metal on the magnet in the pan. I am considering changing the output sensor and the Transfer shaft speed sensor just to eliminate bad sensors. Any ideas on this problem?

 

To clarify: there was no Metal on the magnet just small amount of fuzz. The van has 105k miles.

 

All 3 sensors changed and the problem persists. i had a transmission shop diagnose the trouble codes and they conclude that there is electrical interference coming from somewhere that is inducing a spike voltage in the transfer shaft speed sensor wiring thus setting the P0792 code. With this info I have changed plugs and wires and I am replacing my alternator tomorrow. I am looking for any other information that could cause this issue, any help is greatly appreciated

 

Think you may have the IPM fuse box under-contacts to clean, common problem on here. And check and plugs connected to your trans...Have yet to do this on my own car just to show how bad they were. I've no problems thou...

 

If you do find contact problems picture it on here please.

 

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 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.

 

if anyone has a wiring diagram for the pcm on a 2010 Town and Country that would be of great help

 

You have a Petrol Voyager, so you don't by any chance have the burnt wires syndrome near the exhaust pipe work do you...

 

Googs, I am going to bypass the wiring harness and run a new set of wires for the intermediate shaft sensor and see it my problem goes away. I have a run of shielded wires so I can eliminate emf interference also. Bypass surgery will comence on Thursday
If it solves the problem, then I will dig deeper for future potential problems.
If it does not solve the problem then a new PCM(used) will be next

 

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