My TOD check light came on. I've only used the 4wd system once,months ago. Why would the light come on now ? I drove to a meeting, the Trooper sat for a couple of hours then on the way home the tod check light came on. Any ideas as to what may have caused this?

Sounds like your shift on the fly actuator may be sticking (vacuum actuator, drivers side front axle). You should manually turn 4x4 on/off once or twice a month to keep the SOTF actuators from sticking. Could try to give it a tap with a mallet, or remove, clean up/replace the SOTF actuator. G/luck
Joel