My question has already been settled.

The answer was given by Manfred Jahn :
Did this test with an aircraft model ...
For this enormous knowledge fund I love this forum
...
In a slightly modified form, the LUA script looks like this:
Code:
!lua
if varget("A:LIGHT STATES", "Mask") & 0x0004 > 0 then
varset("T:EmissiveTexture", "string", "porsche_carrera_gt_emissive.dds")
varset("T:EmissiveScale", "number", 1.00)
else
varset("T:EmissiveTexture", "string", "")
end
This script turns on the Night Map of the taillights with the Landing Lights switch:
View attachment 51932
The dynamic lights (headlights and taillights) as well as the Night Map are switched on via the Landing Lights Switch