02 Silverado "service 4WD" light

I got my '02 Silverado 1500 4WD stuck in a snow drift yesterday, all the way up to the frame rails. While waiting for a tow truck, I rocked the truck back and forth in AUTO4WD mode, got on it a little bit, almost got unstuck...but not quite. The tow arrived and winched me out without any problems...after which my "Service 4WD" light came on and all the 4WD buttons on my dash are dead.

Crawled under the truck when I got home and can't see anything wrong with wiring around the transfer case, nothing packed with snow or anything. I was just wondering if there are maybe some related wires on the front diff that might have gotten torn up?

I've read other forums that suggest everything from re-soldering switch wires to yanking the battery for a half hour, to replacing the transfer case. My local AutoZone's code reader showed nothing.

with any service 4WD Lt you need a OEM drivetrain specific dtc code reader....

not all diagnostic readers are designed to read these codes..

with this code taken we here can get you in the right direction..

I would guess that it would be wires got damaged if it was buried in hard ice / snow which would be the only condition that would require the tow truck...

you should also replace ALL the drive train fluids if you feel you over did it...