Door Locks: Description and Operation

Locking Doors

To lock the doors automatically, a momentary pulse of battery voltage is applied from terminal 4 of the Automatic Door Lock Module to the Lock Relay coil through the LT BLU (195) wire. This operates the Lock Relay and the Door Lock Motors in the same way the Door Lock Switches do.

The solid state Automatic Door Lock Module provides this pulse of battery voltage immediately after the Gear Selector is shifted out of P (Park) and the following 3 conditions are present.

1. No ground at terminal 1 (all doors closed).

2. No battery voltage at terminal 7 (Gear Selector Switch not in PARK).

3. Ignition Switch in RUN.

Unlocking Doors

The automatic unlock occurs when the Gear Selector Switch is returned to the PARK position. This provides battery voltage to the Park Input, terminal 7. Momentary battery voltage is then provided at the Unlock Output, terminal 2. This operates the Unlock Relay of the Power Door Locks System.

Central Door Unlock

The Automatic Door Lock Module also provides unlocking voltage to the Power Door Lock System when the key is used to unlock the front doors and is held in the UNLOCK position for 2 seconds. (If vehicle is not equipped with Theft Deterrent the Central Door Unlock will only operate from the LH Door Lock Cylinder Switch. Only Theft Deterrent equipped vehicles have a RH Door Lock Cylinder Switch.) This action grounds terminal 5 the Key Unlock Input. The Module then provides a momentary battery voltage pulse from terminal 2 to the Door Lock Relay to unlock all doors.