1. Remove the high-mount brake light.
2. Fold the rear seat back.
3. Remove the fasteners.
4. Pull the rear package trim upward, then disengage the clips from the body.
5. Disengage the hooks, then remove the rear package trim.
6. Install in the reverse order of removal.
Mazda 6 Service Manual: Rear door speaker removal/installation
1. Disconnect the negative battery cable.
2. Remove the rear door trim.
3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.
Rear Door Speaker Installation Note
Attach the speaker with the wiring harness placed in the groove of the door
unit panel.
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Mazda 6 Service Manual: Theft-deterrent control module inspection
1. Remove the theft-deterrent control module without disconnecting the
connectors.
2. Measure the voltage at the theft-deterrent control module terminals as
indicated below.
3. Disconnect the theft-deterrent control module connector before inspecting
for continuity at terminals L, Q, S, T, a ...