Disconnect the 10P connector (A) from the actuator (B).
Check for continuity between the terminals.
There should be continuity between the No. 6 [No. 9] and No. 5 [No. 10] terminals when the door lock knob switch is in the LOCK position and no continuity when the switch is in the UNLOCK position.
There should be continuity between the No. 7 [No. 8] and No. 5 [No. 10] terminals when the door lock knob switch is in the UNLOCK position and no continuity when the switch is in the LOCK position.
[ ]: RHD model
If the continuity is not as specified, replace the door lock actuator.