Power Locks: Description and Operation

The Power Door Lock system operates to lock or to unlock all doors with the actuation of a single Door Lock Switch. Power is available at all times from the PWR ACCY Fuse A through the ORN (540) wire to the Left Front Power Door Lock Switch, the Right Front Power Door Lock Switch, and the Rear Power Door Lock Switch (except cutaway models). This voltage is also supplied to the Power Door Lock Relay and the Power Door Lock Control Module. Both the relay and the module are grounded by the BLK (150) wire at Ground G201 or Ground G201 and G200 (Upfitter Provisions)

Each of the Door Lock Cylinder rocker switches have two contacts. When the upper portion of the rocker switch is depressed to unlock the doors, one contact closes to apply voltage on the WHT (194) wire. This voltage is applied to the Unlock coil in the Power Door Lock Relay. Since the other side of the relay's coils are grounded by the BLK (150) wire at Ground G201 (Base) or at Ground G200 (Upfitter Provisions), the coil energizes when voltage is applied. Relay contacts then operate to apply voltage on the TAN (294) wire. The relay contacts are normally connected to ground. When the Unlock relay operates, it's ground connection is broken but the contacts of the Lock relay remain connected to ground. Thus voltage and grounding are applied to each Power Door Lock Actuator Motor and the motor operates in the direction required to unlock the doors.

When the lower portion of the Power Door Lock Switch is depressed to lock the doors, the other contact closes to apply voltage On the LT BLU (195) wire. This voltage is applied to the Lock coil in the Power Door Lock Relay. The Lock coil energizes and contacts operate to apply voltage on the GRY (295) wire. When the Lock relay operates, it's ground connection is broken but the contacts of the Unlock relay remain connected to ground. Again, voltage and grounding are applied to each Power Door Lock Actuator Motor and the motor operates in the direction required to lock the doors.

The Side Door Lock Actuator Motor will not lock the door if the door happens to be open. Logic is provided to lock the door after it is closed. With the side door open, actuation of the Lock function will lock the front and rear doors immediately. However. the Side Door Lock Actuator Motor will not operate because the contacts at the Side Door Contact Plate are open. However, the Lock command is represented as a voltage on the LT BLU (195) wire to the Power Door Lock Control Module. The Power Door Lock Control Module senses that the Side Door is open by the grounded signal from the Side Door Jamb Switch on the WHT/BLK (158) wire. When the Side Door is open and the Lock command is observed, the control module enables the delayed operation of the power door locks. It waits for the Side Door Jamb Switch to open with the closure of the Side Door. With the door closed, a timer is set and starts timing. After approximately five seconds, the Power Door Lock Control Module produces another Lock command. The voltage on the LT BLU (195) wire actuates the Power Door Lock Relay to operate all Power Door Lock Actuator Motors to lock the doors. Since the side door is now closed, contact is made through the Side Door Contact Plate and the Side Door Locks.

If, during the five second delay, the Side Door is again reopened, the Power Door Lock Control Module will remain enabled and waits for the side door to close again. It will lock the Side Door five seconds after it closes. If, while the side door lock logic is set, the command to unlock all doors is received by the module on the WHT (194) wire, both the logic and the timer are reset. The Side Door will not be locked even if the door is already closed.