FlyCrestline

The "Service 4WD" Light lit up. Made it home shut down the truck, restarted and it stayed off.
Is the warning light a mileage driven thing or are there sensors in the xfer case and 4WD train
detecting? If its a sensor thing, what sensors are coding? I gotta have 4WD in mountain snow.
Any help appreciated

nothingbutdarts

Just for the heck of it, it might be nice to know details of your truck!

marathon

My '17 3500 would suddenly go into 4wd even on the highway while towing and then the service light would come on. Turned out to be 4wd module, about a $750 part.