VegasJen

hey guys. i have an automatic in the right vehicle, a '94 chevy 3500. got a problem though. just a couple weeks ago it started shifting strange. can't really describe it any better than that, other than to say that when it downshifts into passing gear it will rev the engine to 4k (redline in a diesel) and will hang there untill i ease out of the gas for an upshift. if i'm just driving easy, everything seems to be fine. if i have to accelerate, either passing or starting fast, it doesn't want to upshift.
i don't even know where to start with this thing. i hate slushboxes anyway. if it helps, it's a 4L80E.
i went ahead and changed the ATF and filter because it hadn't been done in an (embarrassingly) long time :bb but that has not improved matters.
the other thing is because this uses a fly-by-wire throttle (see, interesting trivia, the c5 was NOT the first g.m. vehicle to use FBW), there is no kick down cable or TV cable. at least not to my knowledge.
any suggestions?

BSeery

the 480LE is 100% computer controlled. You need a scan tool or appropriate transmission version to read what it's doing.

May be time to call AAMCO.