Take the appropriate action and verify that the warning light turns off.

Taking Action
Message Indicated on DisplayMazda 6 Owners Manual: Headlights
Turn the headlight switch to turn the headlights and other exterior lights on
or off. When the lights are turned on, the lights-on indicator light in the instrument
cluster turns on.
NOTE
If the light switch is left on, the lights will automatically switch
off approximately 30 seconds ...
Mazda 6 Owners Manual: Liftgate adjustment
1. Measure the gap and height between the liftgate and the body.
2. If not as specified, loosen the liftgate hinge installation bolts or the
liftgate striker installation screws, and reposition the liftgate.
Clearance
a: 3.0-7.0 mm {0.12-0.28 in}
b: -1.0-3.4 mm {-0.04-013 in}
c: 2.8-5.2 mm ...