I think you should try to check switch and replace if necessary. Or you use OBD2 scanner to diagnostic what wrong with your car before doing somethings next.I was driving in 4 high last week and shifted back to 2 high but serv 4WD light came on and has been on for a week now. Stuck in 4 high. No noises , no codes , no ABS lights. Visit AutoGuysLand to review best pex crimper if you may concern. Tried disconnecting both batteries for an hour with no change. Any ideas ?