I need to find out is there any way to check if there is a code on my 2004 Durango? like turn key on and off or something to make it show me code? im having several issues that all started yesterday and it first was acting like the tranny...but a friend said to unhook the positive battery cable for 10 min or so and it would reset the computer...tried it now it is idling funny surging between 500 and 1500 rpm...not shifting right....surging while driving....idling at 500 then dies....and the rear heat will not blow hot air only cold and this all started after the battery was disconnected...except for the tranny not wanting to shift into third just started yesterday

 

Turn the key from off to 'on' (not start) three times ending with the 'on' position. The odometer will flash the code or it will read 'done'. This may not work on the 2004.
FF