I will try putting a deaper pan on it to see if that fixes the problem, and I also found the receipt to the sensor and it shows the year make and model of the parts and they were also bought straight from a dodge dealer

 

What's the part number on the sensor?

 

68164850-aa

 

Well, by the part number that is correct..... I would ask if that number is also printed on the sensor... but, it's probably a little hard to see currently.......

How long before the light comes on after you start driving? Does it come on around town as well?

 

Today for example, around town kept it under 60 and drove roughly 30 35 miles and no light, it seems to me it only comes on when on the express way. also couldn't find a spacer or a deeper pan under 100, summit wants 132 for a trans pan that's nuts.

 

Do you have an aux. trans cooler? Or just the one in the radiator?

 

That I'm not sure of, the lines go to the radiator then they go to another thing that looks like a radiator but smaller and then to the trans.

 

Yea it does have one

 

Yep, that would be the aux cooler.

Backflush the lines/coolers. (disconnect them at the trans, and flush the cooler, do NOT flush the trans. Well, unless you WANT to rebuild it......) See if that makes a difference.

 

If the trans temp is not getting above 50 degrees
the computer will not engage OD or TCC per the manual:

TRANSMISSION FLUID TEMPERATURE
THERMISTOR
Transmission fluid temperature readings are supplied
to the transmission control module by the thermistor
(Fig. 6). The temperature readings are used to
control engagement of the fourth gear overdrive
clutch, the converter clutch, and governor pressure.
Normal resistance value for the thermistor at room
temperature is approximately 1000 ohms.
The PCM prevents engagement of the converter
clutch and overdrive clutch, when fluid temperature
is below approximately 10°C (50°F).
If fluid temperature exceeds 126°C (260°F), the
PCM causes a 4-3 downshift and engage the converter
clutch. Engagement is according to the third
gear converter clutch engagement schedule.
The overdrive OFF lamp in the instrument panel
illuminates when the shift back to third occurs. The
transmission will not allow fourth gear operation
until fluid temperature decreases to approximately
110°C (230°F).
The thermistor is part of the pressure sensor and
is immersed in transmission fluid at all times.

So maybe your going slow enough around town to
keep it above 50 degrees but on the highway it cools
down to much and disengages.
Where you live?

Dave