Anyone know how to get into a service menu on the D1 ?

You could try to find the screens that we found over at Corvette Forum (GM product) -- and that were duplicated in the Range Rover's (Ford product) nav. All of the nav systems that are built by Denso share an awful lot of code.

Codes 660, 9448, and 295660 work in our unit. Maybe one of those will work for you? There's also the 1791 code that Denso was fond of as a default, and the 751 and 134679 codes that work on Range Rover units.

Some step-by-step images are posted here, which might help you find your "hotspots" for the keypad.
http://forums.corvetteforum.com/showthr ... 1556247521

Hold Reset and DVD eject. Let go of reset. You may close the screen to the regular position with the Open button when password screen comes up.

Using the joystick, enter [up] [up] [down] [down] [push in joystick]

All you really need to do is up-up-down-down-[press in].
I think someone misinterpreted the "next step" arrows as "right".

I actually did do the arrow right and it worked. Guess if the short way works too ...