I have a 99 JGC with 92000 miles on it. The Check engine light just came on 2 days after taking it off road. I had no idea the trail was going to be as bad as it was. Well now there are like 2 issues that may be related. There is a hose that goes into the front axle that became disconnected which had a fitting on it, so i pushed it back into the hole. Now I believe that this is some form of a vent hose after speaking w. the dealership. But now the check engin light is on and in the mornings and when cool, it does not want to shift gears until it warms up. I am assuming that the check engin light is going to send out a code that will say what this is, but I was looking to see if anyone had any ideas on what I can check on until I can get it in for my appointment.

check trans fluid level. also shift linkage may be bent or damaged causing hard shift. look for leaks and damaged trans pan. haines manual for about 20 bucks will tell how to pull codes without a tester and what they mean. good luck!