System Components

WARNING: This page is about a different car, the 2017 Kia K900. However, it is still accessible from the selected car via links, so may be relevant.

PTL drive unit (A).

Fig 1: Locating PTL Drive Unit
Courtesy of KIA MOTORS AMERICA, INC.

Installed inside the LH trunk trim of the vehicle, it uses the gear motor to automatically open and close the trunk connected to the push rod. It is composed of ECU and drive unit, which is composed of drive bracket, gear motor, push rod and drive arm.
Power latch assembly (A)

Fig 2: Locating Power Latch Assembly
Courtesy of KIA MOTORS AMERICA, INC.

It delivers the trunk lid opening/closing signals to the power trunk module drive unit, and keeps the binding of the power striker shaft with the pawl switch input. It is composed of power latch and cinching actuator.
Cinching actuator (A)

Fig 3: Cinching Actuator
Courtesy of KIA MOTORS AMERICA, INC.

It delivers the trunk lid opening/closing signals to the power trunk module drive unit, and keeps the binding of the power striker shaft with the pawl switch input. It is composed of power latch and cinching actuator.
SMK

Fig 4: Locating Power Trunk Module Button
Courtesy of KIA MOTORS AMERICA, INC.

Press the power trunk module button (A) on the SMK for over one second to open.

* There is no closing signal by SMK.
Trunk inner switch (A)

Fig 5: Locating Trunk Inner Switch
Courtesy of KIA MOTORS AMERICA, INC.

It is installed on the trim inside the trunk and it cannot be operated while the trunk is closed.

With a closing switch input, the PTM unit transmits the trunk locking signal to SMK.

On receiving the signal, SMK performs FOB authentication at the bumper antenna. If registered FOB key is detected, it will search the interior area.

If all doors are closed and there is no FOB key inside the vehicle, SMK transmits the door locking command to DDM and trunk closing command to PTM.

DDM and PTM carry out the command to lock the doors and close the power trunk.
Trunk glove box switch (within the Glove Compartment)

Fig 6: Trunk Glove Box Switch (Glove Compartment)
Courtesy of KIA MOTORS AMERICA, INC.

It is mounted in the passenger side glove compartment. It is used to limit power trunk open/close operation.

In other words, it cuts-off the trunk lid relay and prevents the P-Latch power from being supplied, and deactivates power trunk operation.