I have a 1999 Chevrolet Silverado Z71, and for the past few days the "Service 4WD" light has been coming on. Does anyone know what this means?

 

Do you have a superchip? My superchip makes my light come on

 

No, I'm 100% stock. Thanks for your help though! I called the dealership and they said it could be anything from a faulty switch, to something inside the transfer case. Im gonna hope its a faulty switch.

 

Do you use your 4wd often? B.C on the 99's the transfer case had some problems.

 

I was talking to one of the tech at the shop I work at, and He said to the switch, because when that switch goes out, that will lock up the transfer case and if you are crusing at 65 down the intestate and that goes out, you are going to be in a world of hurt. I am having him do the switch, and my drivers window on my 2000 silverado ASAP.

 

I had the same problem and mine was the 4wd switch. a friend of mine had the same problem with his 2000 and his was the switch also...

 

Myself and a friend with '99 Z71s have both had to replace that switch. That was over 2 years ago and they're still working.

 

I have been through three switches before 40,000 on my 2000 Z-71 ext. cab 5.3 L Silverado. At least those were under waranty. Good Luck

 

My light just came on today on my 3500 Silverado. I see that it might be the switch. Is that the switch on the dash everyones talking about? Or is it a different switch. Can someone let me know.
Thanks

 

It is probably the selector switch on the dash. I have a 99 Z-71 with 97k miles and have never had the problem but a friend with a 99 4x4 had the same "Service 4WD"issue and his was the switch as so many have atested to. It sounds like the dealer was wanting to run up the bill with his suggestion that it was in the transfer case. Just change the switch and you should be OK.