Power Locks: Description and Operation

POWER SUPPLY AND GROUND
Power is supplied at all times
^ through 10 A fuse [No. [28], located in the fuse block (J/B)]
^ to key switch terminal (3)
Power is supplied to BCM terminal (69) through key switch terminal (4) when key switch is in ON position (key is inserted in the ignition key cylinder).
BCM is connected to LCU01 LCU02, LCU03 and LCU04 as DATA LINE A-1 or A-2.
When door switch is in OPEN position, ground is supplied
^ to BCM terminal (32) or (37)
^ through front LH or RH door switch terminal (1).
When door is unlocked, ground is supplied
^ to each door LCU terminal (5)
^ from terminal (2) of each door unlock sensor.
When the door is locked with the key, ground is supplied
^ to LCU01 or LOU02 terminal (7)
^ from terminal (3) of the key cylinder switch LH or
^ from terminal (1) of the key cylinder switch RH
^ through body grounds (M14) and (M47).
When the door is unlocked with the key, ground is supplied
^ to BCM terminal (31) or (27)
^ from terminal (1) of the key cylinder switch LH or
^ from terminal (3) of the key cylinder switch RH
^ through body grounds (M14) and (M47).
When lock/unlock signal is sent to BCM or LCU, BCM sends a lock/unlock signal to LCUs via DATA LINE A-1 or A-2. LCUs then supply power and ground to each door lock actuator.

OPERATION
^ The lock & unlock switch (SW) on driver's door trim can lock and unlock all doors.
^ With the lock knob on front LH or RH door set to "LOCK", all doors are locked. (Signals from front door unlock sensor)
^ With the door key inserted in the key cylinder on front LH or RH door, turning it to "LOCK", will lock all doors; turning it to "UNLOCK" once unlocks the corresponding door; turning it to "UNLOCK" again within 5 seconds after the first unlock operation unlocks all of the other doors. (Signals from front door key cylinder switch)

However, if the ignition key is in the ignition key cylinder and one or more of the front doors are open, setting the lock & unlock switch, lock knob, or the door key to "LOCK" locks the doors once but then immediately unlocks them. (Combination signals from key switch, front LH or RH door switch and front LH or RH door unlock sensor) - (KEY REMINDER DOOR SYSTEM)