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 {0.11-0.24 in}
d: -1.2-1.2 mm {0.05-0.05 in}
e: 2.8-5.8 mm {0.11-0.22 in}
f:4.0-8.0 mm {0.16-0.31 in}
3. Tighten the bolts or screws.
Liftgate disassembly/assemblyMazda 6 Service Manual: Indication/Indicator Lights
These lights turn on or flash to notify the user of the system operation status
or a system malfunction.
*Some models.
*1 The light turns on when the ignition is switched on for an operation check,
and turns off a few seconds later or when the engine is started. If the light does
not t ...
Mazda 6 Service Manual: Cargo compartment light switch inspection
1. Remove the liftgate lower trim. (See LIFTGATE LOWER TRIM
REMOVAL/INSTALLATION)
2. Disconnect the cargo compartment light switch connector.
3. Inspect for continuity between the cargo compartment light switch
terminals using an ohmmeter.
If not as specified, replace the liftgate lock.
...