Ok here is my problem.
My buddy has a pretty sweet snap-on computer. He hooked it up to my 2001 Caravan because it was not shifting. Found out that my van was in "limp mode". The code "P0605" says internal trans controller failure. Ok first question where is it at on the transmission. Can someone who is not a mechanic but is not a dummy change it? Also while my buddy was looking at all the info that his $8,000 computer was giving, it showed that my transmission temp was 1024 degrees. He read that the limp mode could kick in if the tranny over heats. I know the tranny is not that hot is was cold when he teasted it. In another screen on his computer it said transmission was "cold" 2nd question is there a heat sensor that could be bad or is it all the same thing "internal trans controller". I tried to find out something about this but I cant. I found your forum and thought these guys know alot. Please advise. Thank
Lenny.....PA :gr_patrio
Rick99
08-31-2007, 06:15 AM
Post 8 of the thread below has a link to the powertrain diagnostic manual for an 02 Dodge Neon, which has exactly the same tranny as our vans. The diagnostic manual has procedures for each code.
I looked up your code quickly and it says to check the wiring and all ground connections-- that's an important step before you go to the expense of replacing the TCM. Carefully check the wiring harness for corrosion or damage (part of it wraps around the front of the tranny near the bottom and can be damaged if you park into a curb. The ground can also be corroded. If the ground strap (at the top of the tranny toward the front) looks like it's in good shape, disconnect it anyway and clean up the ends with some sandpaper then reinstall.
If that doesn't solve your problem, the next step in the manual is to replace the TCM. That will require some kind of initialization-- you'll have to set the pinion factor and run a "quick learn". I can't remember if you have to program in the VIN or anything like that. Your friend's scan tool might have those capabilities. Actually replacing the TCM shouldn't be too hard.
Transmission Diagnosis and Removal Thread (http://www.dodgetalk.com/forums/showthread.php?t=150579)
lenren2004
08-31-2007, 08:47 AM
Thank you for the response. Where is the TCM located? Does the TCM control the temp readings? Is it safe if I drive it in limp mode? I dont take it over 45mph at 3800 rpm. I just dont want to damage anything while looking for parts. Is it safe to by a used TCM?
Thanks,
Lenny...PA
Rick99
08-31-2007, 09:39 AM
I'm pretty sure the TCM is toward the front behind the driver's side wheel-well. Follow that harness that goes under and to the front of the tranny. Will a used TCM work? I've never tried that, but in theory it should. You'll still want to set the "pinion factor"-- which means setting it up for the size tires you have if different from the donor van-- probably not a huge deal, but could throw your speedo off. The trans temperature reading should go through the TCM. By the way, did you have the engine running when you checked the temp-- for some reason, mine always reads a trans temp of something like -50F (which would be cold for CT in July) until I start the engine, then it becomes reasonable.
lenren2004
08-31-2007, 12:36 PM
Yes I had the engine on when he tested it. I dcided not to go with a used one but with a referb one for $249.00. Deal? I looked around for the TCM and didnt find it. So while I was talking with the dealer they said it would cost around 50 bucks to install it. Which seems fair to me. Having them worry about the relearn and pinion makes it well worth it. The biggest concern for me is the temp reading we got 1024 degrees. I would hate to replace the TCM if there was a temp sensor bad. Is this possible? Would a different code come up for a bad sensor. Is the code I got a generic code just saying something is wrong somwhere and the TCM is failed? I dunno Should I have sensors checked or is everything run through the TCM and that heat reading has to do with the TCM bing bad.
