1. Pull the rear scuff plate upward, then disengage clips A, pin B, and hooks C from the body, and remove the rear scuff plate.

2. Install in the reverse order of removal.
Front scuff plate removal/installation
C-pillar trim removal/installationMazda 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.
...
Mazda 6 Service Manual: Oil pressure switch inspection
Caution
Water or foreign objects entering the connector can cause poor
connection or corrosion. Be sure not to drop water or foreign objects on the
connector when disconnecting it.
On-vehicle Inspection (harness inspection)
1. Disconnect the negative battery cable.
2. Remove the under ...