1. Connect the WDS or equivalent to the DLC-2.
2. Measure the PID value.
Note
PID/DATA MONITOR AND RECORD function table

Dtc p0841
TroubleshootingMazda 6 Service Manual: Replacing a Wheel
WARNING
Always use wheels of the correct size on your vehicle: Using a wrong-sized
wheel is dangerous. Braking and handling could be affected, leading to loss of control
and an accident.
CAUTION
A wrong-sized wheel may adversely affect:
Tire fit
Wheel and bearing life
Ground clearance ...
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.
...