Key is VSS not working. Repair that first. Then see if you have overdrive.

Symptoms of non operating VSS are:

Firm shift feel, abnormal shift schedules, unexpected downshifts may occur at closed throttle. No 4th gear, no engine braking in 2nd or 3rd gear. No torque converter clutch apply. May flash TCIL.

Repair your VSS.

Bob


An ounce of prevention provides a pound of cure!