Description and Operation

Description

System Overview: The larger the door, the more difficult it is to close. Quite often, people are seen driving with a door that is not fully closed. The power door latch partially solves this problem: if the driver or passenger gives the door a slight push, it fully closes the door. Partial closing of the door is generally known as the 1st latch, and full closing is known as the 2nd latch. The main features of the system are as follows.

• Installed on all four doors.
• Consists of the door lock actuator and the soft close actuator.
• Locks/unlocks the doors using signals from the DDM and ADM.

System Structure: The following is a diagram of the driver's door lock and power latch. The DDM detects and controls the power and switch status (lock/unlock switch, door key switch) for locking/unlocking and activating the power door latch, and the power latch function operates independently.

Latch and Actuator: Together known as the door lock actuator, and as the part on which the striker engages when the door is closed.

1. 1
   Latch: Identical in design to conventional latches and includes an SCA cable that supplies the power required for partial-close closing of the door.
2. 2
   Actuator: Contains the door lock/unlock motor, lock/unlock position detection switch, and door key detection switch. Power door lock actuators are also equipped with a dog switch and an ajar switch, which report to the SCA.
3. 3
   ECU: The ECU controls the SCA by monitoring the positions of the ajar and latch switches and determining whether the power lock function should be used. The ECU is built on the circuit board inside the SCA.
4. 4
   Closing Motor Power: When a signal is received from the ECU, the soft close motor rotates to close the door, then returns to standby for the next activation signal.
5. 5
   Hall Sensor: The Hall sensor is mounted on the printed circuit board and detects the initial position of the power latch by detecting the location of the magnet attached to the gear.
6. 6
   Ajar Switch: "Ajar" means slightly open. The ajar switch determines whether the striker is fully engaged with the latch when the door is closed. This switch is installed inside the door latch and is linked internally. The switch reaches its full state as the signal changes from On to Off. Because the switch is installed inside the actuator, it cannot be inspected separately. To perform the test, use the external connector and measure the voltage change.
7. 7
   Dog Switch: The dog switch is activated when the door is partially closed. The power door latch function is turned off when the off signal is transmitted. Like the ajar switch, the dog switch is installed inside the actuator and must also be checked for voltage change using the external connector.
8. 8
   Ajar and Dog Switch Activation: These switches have the following activation pattern:

   Switch	Door Ajar	Door Closing	Door Closed
   Ajar Switch	ON	ON	OFF
   Dog Switch	ON	OFF > ON. Internal link changes the contact status.	OFF
   Power Latch	Inactive	Active	Discontinued

SCA (Soft Close Actuator): The SCA uses its power closing motor to fully close partially closed doors. Power Door Latch Switch: The power door latch function must first determine whether the door is fully or partially closed. This is achieved by the switch located inside the latch (door lock actuator) and the body wiring harness.