98 cherokee overdrive not working?

98 4.0 aw4 231. Once in awhile it wouldn't have overdrive. Turn it off and back on and it would be fine. Now I have no overdrive at all. Just 1 2 3. All work fine no slipping erratic shifting etc. tps is new and neutral safety switch works fine. Any suggestions? Can't seem to narrow it down!!

Adjust your TV cable, and also, disco the TCU. And drive/shift manually to see if you get OD. If so, chances are your TCU is failing.