Achieva V6-3100 3.1L MFI VIN M (1994)
Power Door Lock Switch: Description and Operation
CIRCUIT OPERATION
When a Front Door Lock Switch is activated in the "LOCK" or "UNLOCK" position, all of the doors lock or unlock in unison. Each lock can also
be operated manually from the locking knob. In addition, with the Ignition Switch in "RUN," all Power Door Locks are automatically locked when
the gear selector is moved from the "PARK" or "NEUTRAL" position or when the vehicle reaches a certain speed. The locks are operated by
reversible motors that receive voltage from two relays in the Automatic Door Lock Relay. These relays operate to turn the motors on by applying
voltage to one side of the Door Lock Motors and a ground to the opposite Door Lock Motor terminals.
When either Front Door Lock Switch is moved to the "LOCK" position, battery voltage is applied through the CKT 195 to the lock relay coil of
the Automatic Door Lock Relay. The Automatic Door Lock Relay is energized, closing the door lock contacts and applying battery voltage to the
Door Lock Motors via CKT 440 through the CKT 295. Ground is applied to the opposite motor terminal through the normally closed unlock relay
contacts within the Automatic Door Lock Relay. The Door Lock Motors then lock their respective doors.
When either Front Door Lock Switch is moved to the "UNLOCK" position, battery voltage is applied through the CKT 194 to the unlock relay
coil of the Automatic Door Lock Relay assembly. The door unlock relay is energized, closing the door unlock contacts and applying battery
voltage to the Door Lock Motors via CKT 440 through the CKT 294. Ground is applied to the opposite motor terminal through the normally
closed lock relay contacts within the Automatic Door Lock Relay. The Door Lock Motors then unlock their respective doors.
The Automatic Door Lock feature is controlled by the Multi-function Alarm Module. With the Ignition Switch in "RUN" and the gear selector
moved from the "PARK" or "NEUTRAL" positions, the ground signal that is applied to the Multi-function Alarm Module from the instrument
Cluster via CKT 1286 is removed. The Multi-function Alarm Module then momentarily applies battery voltage to the Automatic Door Lock Relay
via CKT 195. All doors lock as described above. If the Multi-function Alarm Module receives a vehicle speed signal without having seen a ground
signal on CKT 1286, it momentarily applies battery voltage on CKT 195 to lock the vehicle doors. The module will lock the doors once per
ignition cycle. The Multi-function Alarm Module receives a vehicle speed signal from the Engine Control Module (ECM). If the Multi-function
Alarm Module receives a speed signal indicating that the vehicle is travelling faster than 8 mph and the module has not received a ground signal on
CKT 1286, it will momentarily apply battery voltage on CKT 195 at the Automatic Door Lock Relay to lock the doors. If the front doors are open
they will lock upon closing.
The Door Unlock Module unlocks all doors when it receives "ignition off" input from CKT 39 (Gages Fuse). When the DUM senses ignition off,
it applies battery voltage to CKT 194 to unlock the doors. The DR UNLK fuse has been designed as a disable feature for the Automatic Door
Unlock Module. If the DR UNLK fuse is removed, the Automatic Unlock feature will not operate.
