Service 4WD light problems 02 Duramax
 

I have a 2002 Silverado 2500HD. My problem is the Service 4WD light! I have had the Transfer Case Switch replaced and have cleaned the ground to the frame (a hint I found on this site), but it is still doing the same thing. My local Chev service department is now trying to blame this problem on the command start, so I tried not using the command start and started it only by key….but it did not change anything.

Our weather here has been on the cold side…anywhere from -35F to 0F. The problem tends to be worse when the weather is colder. In order to shift it in and out of 4WD, sometimes just restarting it will give me a small window of time to shift it before the Service 4WD light comes back on and locks the shift switch. Other times, I have to remove the 4WD fuse and let it sit for abit, replace the fuse and I can usually shift it then….but eventually the Service light will come back on. Needless to say, this is impossible to do on the fly :dang:

This is my first winter with this truck, so I don’t know if it has always had this problem or not, but I cant seem to find a place that can tell me what needs to be fixed! Please Help

sounds like the servo motor to me I put one in my 03 easy to install kinda spendy good luck