Hi Tom, there are two locations on your LS that display oil maintenance reminders. I'll give you instructions on how to reset / turn off both.
To reset the oil maintenance data on the instrument panel you must:
1. Switch the display to trip meter "B" while the engine is running.
2. Turn the engine off.
3. While pressing (and holding) the trip meter reset switch, press the engine start button twice (foot must be off the brake pedal).
4. Continue holding the trip meter reset switch until the display goes from "Resetting Oil Maintenance Data" to "Complete."
5. Press engine start button to turn off the vehicle.
To turn off the oil maintenance "reminder" from the navigation screen you must:
1. Press the "Menu" button above your remote touch controller.
2. Select "Setup," then "Vehicle," and then "Maintenance."
3. Select "Reminder" at the top of the screen to disable all maintenance reminders.*
*Unlike the maintenance data on your vehicle's instrument panel, the dealer typically does not reset the maintenance reminders on your navigation display. This is customizable by the vehicle owner and works similar to a calendar for individuals who prefer to do their own maintenance. All actual maintenance data, warnings, and reminders will be displayed on the instrument panel.