4x4 transfer case lights, U1000 quick fix [Archive] - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

: 4x4 transfer case lights, U1000 quick fix

02-25-2009, 11:03 PM
During a recent snow storm here in SE Pa. I found that I no longer had electrical access to the 4x4 function switch. The lights had gone out. I had put the selector in A4WD and then 4HI and nothing happened. I contacted ON-STAR and their diagnostic check indicated there was an issue with the transmission having "lost communication" with the transfer case. The ON-STAR employee gave me a U1000 code number. After checking many threads related to similar issues I happenned to speak to another Chevy P/U owner who said he had similar problems. He suggested disconnecting the NEG battery terminal, then reconnecting power a few minutes later. So I took his suggestion and GUESS WHAT ? The power came back on to the lights and I now have a 4x4 vehicle again !!! I guess it was like re-booting a computer by turning it off then repowering.

02-25-2009, 11:09 PM
Cars today have become too advanced for their own good, its like they are more electrical then mechanical. I hope your problem doesnt resurface, at least now you know how to take care of it at least. If it starts up again I would have to strongly recomend that you pull your engine and put in a Carburated Chevy big block motor with another transmission, that should stop all those pesky electrical gremlins.:excited::woohoo: