FWIW since our trucks are a joint collaboration it seems with GM, since they have GM parts I would expect it to be read by anything that will read a GM.

I just did mine the other day and it worked fine, your sure your doing it from the hookup under the dash right? Cause that thing under the hood it seems is only for special scanners (got one at my shop) or a toyota specific scanner tool.

1996 T100, Mickey Thomson Classics, Bridgestone Dueler AT 265/75/16, custom offroad KC's.