Chrysler Repair: 98 Concord transmission, chrysler dealership, transmission controller

Question
My 98 Concord won't come out of second gear.  My wife stopped for gas and when she pulled back out onto the road, this started happening.
 From reading through some other posts, it seems that this is some kind of safety thing that happens when the computer for the trans finds a problem.
 The car has about 35,000 miles and has never exhibited any signs of slipping or any other trans problems.  The fluid is full and a good color and not burnt.  Are there some sensors or other areas that I can test?  

Thanks!  

Answer
Hi Mike,
That is low mileage for a trans problem to appear. I would be inclined to get a fault code readout of the transmission controller using the diagnostic readout box III at a Chrysler dealership. Ask for the numbers, what they mean, what they propose to do, and how much it will cost, and whether the cost of the readout will be deducted from the cost if you authorize the repair? Then write back with the code numbers and other answers and we can evaluate them against the shop manual for the trans. With the self-diagnostics on board it is really best to get the readout because that will tell you what prompted the trans to put itself in "limp-in" mode. Otherwise you are flailing about in a very complex system.
Roland