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Car: 2006 Chrysler 300c
Join Date: Jul 2008
Location: Naples, FL
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This is from another of my posts on another thread a few days ago with the same issue as yours... I'm just copying and pasting it...
First off what I have to say only applies to a 722.1 Nag1 5 speed transmission, I presume it has that in it. Presuming your transmission level is ok then I would put my money on the speed sensors in the transmission are not communicating with the speed sensors outside the transmission. The speed sensors in the transmission are two little round tabs that quite literally hang off the edge of the valve body by two little copper strands. Over time they start to wiggle back and forth, come loose and make some strange issues such as second gear or third gear pull aways etc... What actually happens is they wiggle and lose communication and if it happens when the car is slowing then the transmission won't downshift from its previous gear as it doesn't know its slowing down. When you pull away the transmission is literally pulling away in whatever gear you stopped in. Quick trick to check is when it does it try to use autostick, if the number doesn't change then that's where my money is. Also try driving it in autostick for awhile and you will see what gear it sticks in. The fix is to replace the electronic portion of your valve body in your transmission, it is a straightforward job (1 1/2hrs'ish) and parts are not outrageous if you buy online. I picked mine up off eBay for $150, there were lots available in Europe as well as this gearbox is shared with multiple vehicles (mercedes, Porsche, Jag etc) and the guts are the same. If you look up 722.1 Nag 1 valve body conductor plate you will see the part. The sensors hanging off the end is a common problem, the new revised part doesn't have the same setup and is supported.
* Flushing it WILL NOT WORK... and will also spread a little crud evenly on your other components... dump the fluid... change filter and the conductor plate on the valve body... refill and reset codes and should fix you up just fine.. I bet I have posted this same thing on 10 different threads in the last 12 months it's so common.
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