I have a 99 Sub. with a 6.5TD and auto 4WD. On vacation the service 4WD light came on intermitantly. About 30 miles from home the check engine light came on and the cruise control cut out. We stopped at a store near home to get some bread and when I restarted the truck, it was in 4 wheel drive low. I never touched any of the 4WD buttons. All the lights on the 4WD swithches were out and it would not shift out of 4WD low. The one TDC that was set that I was able to retreive with a simple code reader was P1875. The diagnostice procedure for this code points to either bad wiring on ciruit 1694, a bad transfer case control module or a bad PCM. However, without a tech 2 or similar scanner I cannot confirm any of these (except the wiring on circuit 1694 seems OK, no shorts or opens). I cleared code 1875 and it did not reset. But the Service 4WD light is still on and its stuck in 4lo. I cannot retrieve any transfer case codes. My question is, has anyone seen this problem before, or does anyone have a tech 2 near Springfield, IL that wouldn't mind helping me diagnose this.

Thanks
Bill Riley