I have a 59 plate Honda Accord s type.. when I select auto mode for satnav backlight when I turn on lights it should be a black background but it doesn't change, it works if I do it manually . Any ideas please.

 

This is from a Honda Service News article:
Navi Display Won’t Switch to Night Mode with Headlights Turned On

The reason could be the dash illumination control setting.

Note: Depending on the vehicle, this control could be a ****, a button, or a pair of buttons.

If the control is set to full brightness when the headlights are on, it overrides automatic display mode switching and the display screen stays in “Day” mode no matter if the headlights are on or off.

This fix this problem, here is what you need to do:
1. Start the engine.
2. Turn on the headlights, and adjust the dash illumination control setting from full brightness down a few clicks to middle brightness.
3. Turn off the headlights, and shut off the engine.
4. Start the engine again.
5. Turn on the headlights, and watch the display screen.
- If the display screen switch to “Night” mode, you’re done with this repair.
- If the display screen stays in “Day”, you may have a problem with the Navigation System.

For more information on automatic display mode switching and for recommended display mode settings, check out “System Set-up” in your navigation owner’s manual.