Service 4WD message

On a/my 2000 Silverado LT Z-71 the Service 4WD message was

caused by cold solder joints in the dash 4 button 4x4 push button

switches.... Dealer fixed/ replaced switch problem under GMPP warranty.

I was getting intermittent "Service 4WD" messages on my 03 Silverado LT Z71. I took it to the dealer today to have it looked at before my extended warranty was up and they found it showing code C0550 and that there was a TSB on this problem. The dealer reprogrammed the transfer case shift control module. I have not driven it much today, but seems fine so far, will let you know if problem reoccurs.

Well, almost a month from the day (Apr 27, 2007) that the dealer reprogrammed the transfer case shift control module, my "Service 4WD" message came back on. I took it back to the dealer today and they retrieved code C0327 from computer and they replaced the encoder sensor per Service Bulletin #03-04-21-001D. Fortunately, they waived my $100 deductible on my extended warranty! Hopefully the problem is fixed now!!!