My 97 Mystique has 68,000 miles and has been driven lightly. The transmission was serviced, shifts normally with smooth shifts through all speeds around town, but at highway speeds of 60+ in overdrive it appears to slip as the tach revs up and it searches for a downshift. Although this is intermittent, I can't do any highway driving.
Could this be a transmission range sensor or is this another problem?
Anyone very familiar with this transmission know what might be the problem.
Thank you