Hmmmm - I've worked on quite a few VY and VZ clusters, and never come across this...
However, it may just be that the micro inside the cluster has its knickers in a bit of a knot. It's not that hard to get to the back of the cluster and remove the harness connector for a few seconds - two #2 phillips head screwdrivers, a stubby and a "normal length" one, are all the tools you'll need.
Start by releasing the column lock and drop the steering column down. Use the stubby screwdriver to remove the two screws holding the bezel - they're upside down in the top part of the bezel. Once these are removed, you can pull the bezel along the top edge and it'll pop out.
Again use the stubby driver to remove two upside-down screws from the top cluster mounting tabs, and the regular driver to remove the two screws at the bottom.
Now swing the cluster out from the top edge - before too long you'll be able to see the harness connector - it has a little release lever which you need to swing upwards, and this will pull the plug out for you. Wait a few sesconds, and plug it straight back in. Press it in firmly and the release lever will lock back down.
That might fix it, but if not it might mean a trip to Holden. If it does fix it though, you've probably saved yourself a hundred bucks or more! (I'm sure the "friendly" service staff at your local dealer would charge at least that much...)
Putting it all back together is obviously just the reverse procedure.
Hope it helps. Cheerz!
