2009 dodge 5500 cummins Asin 6 speed automatic problem

[All_I_could_aff]

I am away on vacation and just got the word that one of the work trucks is having transmission trouble again. The truck has a little over 300,000 miles on it, and we put in a jasper transmission in 2014. Less than 20,000 miles on it since then due to the purchase of a new truck soon after that. It seems like it's going into a limp mode sometimes where you can be cruising steady and it will downshift to third gear. If you slow to a crawl and then accelerate again it may be fine for several miles and then do it again.
The driver is reporting that the digital transmission range display on the instrument panel changes at the moment it goes into this limp mode. He says the little rectangular boxes that normally are around the P R N D 3 2 1 go away right as the transmission drops down to third gear. Unfortunately I have our code reader with me in case of trouble on my long drive to Florida, so I am just hoping another Dodge owner with this specific transmission has any input. Thank you

[bguy]

I posted your question on another forum and here is a response. This guy knows his stuff.


This is the Aisin-Warner AS68RC?
http://www.atraonline.com/gears/2008/2008-12/2008_12_40.pdf
If the PRND321 boxes are disappearing, it may be an electrical issue and not mechanical. The TCM may be losing the 'shifter signal' and therefore doesn't know what gear it is in? On some vehicles, all of the indicator quadrant boxes will light up if this signal is lost. If it is between quadrants, the boxes may disappear.
Does playing with the shift lever change anything? The TRS (transmission range sensor) itself is pretty reliable and rarely the problem.
Shift cable adjustment and TRS wiring would be the first suspects on my list.
P0705 and P0706 are typical 'check shifter signal' faults. Have the fault codes read first.
http://www.obd-codes.com/p0705

[carringb]

Do any lights other come on? How about a small round red dot in the middle of the dash? If that red dot lights up, its a bad throttle. It's like the fail safe indicator when the two TPS sensors in the throttle don't agree. For some reason, that particular condition doesn't always light up the yellow wrench. Had it happen on one of our '08 4500s. Never gave us any codes either. Would just lose power and that little dot would light up.

[45Ricochet]

Many things can cause a limp mode, have em stop by a auto parts house so maybe they can pull the code.
Without one we would all just be guessing.

[All_I_could_aff]

Both batteries were replaced a couple months ago, DPF deleted with a new to last year

[donn0128]

Sounds to me like either battery or more likely the ECM throwing emission codes. Quite common on this vintage. The DPF gets clogged, or dies forcing the engine into limp mode.