91 park avenue acting up
 

Came home from out of town, battery was completly dead. Interior light was left on. Jumped it off my Cherokee. Backed out the driveway,, put the car in Drive and it will only downshift to 2nd, not 1st , even manualy. The check engine light is now on and the car is idling at 2000 rpm. And the weirdest part is the A/C is now not working.
So i continue to drive it starting from 2nd gear and sometimes it will shift into 1st. I will then put it into Drive and it works perfectly, the engine light goes off and the A/C all work until i shut the car off and back to all of it not working again. I had the battery load tested and it is good. Can anyone help?