When I am driving at low speeds my 4 wheel drive engages. The only way I can get it to disengage is to back the vehicle up about 12 feet while pressing the 4 wheel drive switch. This has happened off and on for months and the dealer cannot locate the problem. Today the Service Dept. disengaged the 4 wheel switch and asked me to see if anything happens. Has anyone else experienced this problem? Any ideas? Thank You!