I bought my 2006 Dakota last winter with 70,000 miles. I purchased from the original dealership from where it was originally purchased from.
I inherited this intermittent, engine light limp mode problem. The truck ran great until the weather warmed up. THEN IT STARTED.

I read all of the different message boards stating this same problem. I am a pretty good mechanic, but electrical and sensor issues are a PIA. For me, the truck deserved the repair, low mileage and a great price. An R/T with a lot of pep.

I brought the truck to the best and most honest mechanic I have ever dealt with. He has a no nonsense approach to all problems.
After leaving the truck with him for a month, he made the repair.

My invoice stated he had 15 hours into the job.
He replaced the transmission sensor (Standard Parts, part# TCS78 STD V) and the computer.

He stated the sensor had gone bad and the computer kept trying to fix the problem. In this year vehicle the engine and transmission share the same computer. The sensor was sensing the transmission was overheating.

No more problem. I am purchasing a heat sink transmission cooler for good measure. I will install this weekend.

Thanks Moparts message board.