Installed battery, works great. Many Thanks :)

It has been a while, but I seem to remember there was a modification for this problem. The battery to keep the memory fails and there is a replacement battery for it, requires some adapting to fit. Take the display apart and you will see the battery pack with 2 wires to the board, cut the wires and wire in a couple of ni-cad type batteries in of the same voltage and you will be good to go. If you have a friendly dealer close they may have the bulletin to explain the update.
Steve.

can you remove the display and open it up and check inside it to see if it has a battery like a watch battery or cpu type battery on it?
or it could possibly have a bad 'holding' capacitor on it letting the charge for memory drain when battery is unplugged.

if none of these suggestions are possible you may need a new display. Not sure an operators manual would help other than to show you how to set it, you'll probably need to talk to the factory on how this display works, a service manual might tell you something but on this particular problem i doubt it. Of course this is all educated guessing on my part and may not apply here but
maybe someone that works for toyota can shed some light on this?

Also looking for a copy of the operator manual


prenticelift at gmail dot com