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

Taking Action
Message Indicated on DisplayMazda 6 Owners Manual: Interior
Front
Rear
...
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 ...