Transmission finding cold-weather, intermittent limp in mode in warmer weather.
 

My Chrysler 300 M (2003) has developed transmission issue that doesn't appear to be duplicated in this particular forum or anywhere else that I can find. The problem is somewhat intermittent and only occurs when the temperature outside is above 55 to 60°. When the temperature is above this temperature the transmission will occasionally slip into limp in mode after a prolonged drive and you decelerate to a stop. It appears to be related to sustained driving in fourth gear and the transmission being unable to downshift. Proceeding the limp in mode the transmission will have an audible clunk sound. Oddly, turning the car off and turning it back on clears the limp in mode and the car is able to be driven again.

The dealership replaced the solenoid pack and the valve body a year and a half ago and the problem seemed to be gone for "of course the length of the warranty work" one year. But started acting up just before the winter season. I persevered assuming that I only had a few months of driving before the transmission gave out completely. But then the winter months set in and the transmission performed flawlessly for the 3 to 4 months of extreme cold.

I dropped the pan a day ago and there was no extreme issues to report. The fluids fine, no debris in the pan beyond the normal. I did discover however that one of the screws in the valve body had been stripped assumedly by the dealer when the valve body was replaced. I'm very suspicious that this may be the cause of the problem. But I'm hoping that maybe somebody has had a similar issue and can shed some light on this for me.

The code being stored is: P1776 TRANS $18 which is that the solenoid switch valve in the left rear position.

Additional code: P0700 ENG $10 which is as I read it a generic code.

Additionally as I look through the codes there are five I noted:
P1776 MOD $18
P0700 MOD $10

the 1776 is the solenoid pack on teh top of the valve body

Thank you for your reply. Yes, obviously, the code indicates that the solenoid pack is bad. My question is more related to the pathology of the problem rather than the code that the computer is sending. Bear in mind that both the solenoid pack and the valve body have been replaced ( By the dealer in Exton Pennsylvania) in the past year and a half. Additionally why would this problem only propagates when the temperature outside is above 50°?

1776 is most commonly caused by solenoid issues however there are a few other things to check, based on the fact that the dealer already replaced it (there was a TSB about solenoids and date codes)
All wireing and connectors to the trans inspect harnesses and connectors. There are two grey plugs near the master cyl. Follow harness ad check to make sure no rub thru on the rack or tie rod.
Shift cable adjustment should also be checked.
There are also a few TSB's concerning "reflashes" for your car, check with thdealer these were done when the previous work was done.