what kind of scanner? Generic hand-held or a real Chrysler DRB-II scanner? Just asking....there may in fact be codes. There SHOULD be, at any rate. If it's not a DRB type scanner, it's probably not going to work, or tell you very much.
Shifting on your trans is controlled by a governor (pressure valve) and the valve body. The various clutches can be air-pressure-tested statically.
Naturally you want to check your fluid level and shifting linkages before you start tearing anything apart.