I've just fixed this problem on my 01 Grand. After trying everything including a PCM, it ends up being a faulty connection in the Instrument Cluster. For some reason the main DATA BUS seems to run through the cluster.

Other symtoms include driver door not locking/unlocking, dash lights stay on always, gauges don't work.

Quick check, hit the dashboard on the right of the cluster. If the cluster starts working then you have a bad connection. Unplugging the cluster, and plugging it back in fixed all these issues.