These locks are intended to help prevent children from accidentally opening the rear doors. Use them on both rear doors whenever a child rides in the rear seat of the vehicle.
If you slide the child safety lock to the lock position before closing that door, the door cannot be opened from the inside.
The door can only be opened by pulling the outside handle.

Locking, Unlocking with Door-
Lock Knob
Doors and LocksDrive Belt Removal/Installation [Mzr 2.0, Mzr 2.5]
MZR 2.0
A/C drive belt removal
1. Remove the aerodynamic under cover No.2 and splash shield as a single unit..
2. Remove the nut shown in the figure and set the power steering pipe component
out of the way.
3. Set the SST as shown in the figure.
NOTE:
Hold the SST by hand unti ...
Front Side Marker/Front Turn Light Bulb Removal/Installation
1. Disconnect the negative battery cable..
2. Slightly bend back the front mudguard..
3. Rotate the front side marker/front turn light socket in the direction of the
arrow shown in the figure.
4. Remove the front side marker/front turn light bulb.
5. Install in the reverse order of ...
Stop Vehicle in Safe Place Immediately
If any of the following warning lights turns on, the system may have a
malfunction. Stop the
vehicle in a safe place immediately and contact an Authorized Mazda Dealer.
...