Power Locks: Description and Operation
CIRCUIT OPERATIONLocking
When a Door Lock Switch is in the lock position, voltage from Fuse D7 is applied to the Door Lock Relay's lock coil through the closed contacts of the Door Lock Switch and CKT 195. With voltage applied to the Door Lock Relay's lock coil, the relay energizes, allowing voltage from Circuit Breaker 1 to be applied to the Door Lock Motors through the closed relay contacts and CKT 295. The door lock motors lock the doors since they are grounded at ground G301 through CKT 294 and the unlock relay contacts.
Unlocking
The unlocking operation is similar to the locking procedure except the Door Lock Relay reverses the Door Lock Motors polarity. This makes the motors run in the opposite direction, unlocking the doors. When a Door Lock Switch is in the unlock position, voltage is applied through CKT 194 to the Door Lock Relay's unlock coil energizing the relay. The relays unlock contacts now close to apply voltage to the Door Lock Motors through CKT 294. The Door Lock Motors are grounded through CKT 295 and the lock relay contacts at ground G301.
The doors can also be unlocked when the Body Computer Module (BCM) applies voltage from terminal 3D15 through CKT 194 to the Door Lock Relay's unlock coil. The BCM will apply voltage at terminal 3D15 when a Lock Cylinder Switch is turned to the UNLOCK position, grounding BCM terminal 2B3 or 2A4, twice within 10 seconds. The BCM senses a ground at terminal 2A4 when either the LH or RH Door Lock Cylinder Switches is turned to the UNLOCK position. Turning the Trunk Lock Cylinder Switch to the UNLOCK position will cause BCM terminal 2B3 to be grounded.