I'm in Euro mode, but if it's in Imperial gallon units, then I can disconnect the battery and the mode stays the same but it goes back to factory default of US gallons mode. The distance units remain as yards on the nav. This is a pretty well-known issue/solution.

I think going to Euro mode causes gallons to become Imperial, but removing power returns them to US default, but doesn't change the basic mode from Euro to US. Also, once you're in Euro mode/US gallon mode, then selecting metric for units means that it will go back to Imperial gallons if you try to go back from metric.

Since it somehow retains the US gallon memory as its original state, and can get into a Euro/US hybrid mode, I thought maybe Navcoder could also force it into this state.