Check engine light comes on after car is running and service 4 wheel drive is on

I would suggest having the vehicle scanned before going any further. Are there any other accompanying lights on the dash?

More than likely it is the switch alot of electric 4-wheel drive switches have been known to go bad from lack of use

It's most likely going to be the wheel speed sensor which is located at the wheel bearing. when they become disconnected or the wire breaks your abs and traction light will come on and something your check engine light.

What does it mean when the Service 4 wheel drive light come on?

Have you received any failure codes (check engine light)? If you have, find out what they are by going to any parts store and they can read your failure codes for free. Let me know after that.

check the lubricant in the transaxle, if it is low it will cause the light to come on.

The service 4 wheel drive light comes on because there's a problem. The biggest causes of this I've seen are a software glitch in the final drive control module which the dealer can fix by reprogramming and the other is usually the electric actuator on the front axle housing. The only light that comes on by a timer is the one that says, "perform service" in your overhead console or odometer.

There are well over 100 problems in the electronics that turn the service engine soon light on, go to autozone or a kragen and they will run the trouble code test for free, then record that code and post it here. As far as the 4X4 goes that problem is most likely the electric motor that engages the 4X4 tranfer case, u will have to have that tested by either a 4X4 shop or the dealer, the dealer is the best option.

its a possibility that the transfer case might be going out or the fluids in it are bad sometimes after alot of mileage the tranfer case will slip or stick

well just took mine into a shop & it turns out service engine light was a bad locking gas cap I replaced it & wallaa fixed & the light is now off after being reset