Caution
1. Disconnect the negative battery cable.
2. Remove the under cover.
3. Disconnect the VSS connector.
4. Remove the VSS.

5. Apply ATF to a new O-ring and install it on a new VSS.
6. Install the VSS.
Tightening torque
8-11 N·m {82-112 kgf·cm, 71-97 in·lbf}

7. Connect the VSS connector.
8. Install the under cover.
9. Connect the negative battery cable.
Vehicle speedometer sensor (vss) inspection
Solenoid valve inspectionMazda 6 Service Manual: Rear door lock actuator inspection
Door Lock Actuator
1. Disconnect the front door lock actuator connector.
2. Apply battery positive voltage to the front door lock actuator terminals
and inspect the operation of the front door lock actuator.
If not as specified, replace the front door lock actuator.
With double locking ...
Mazda 6 Service Manual: Locking, Unlocking the Doors
NOTE
The system may not operate if you are too close to the windows or door
handles.
If the key is left in the following areas and you leave the vehicle,
the doors may be locked depending on the radio wave conditions even if the key
is left in the vehicle.
Around the dashboard
...