Power Operated Tailgate Module (Pot) [2012-2017]: Function: Tailgate

Courtesy of VOLVO CARS CORPORATION

There are three ways to open the tailgate.

One way is by using the handle on the outside of the tailgate. A press of the switch is enough to open the tailgate, on the condition that the central locking has been activated.

The second way is to press in the button on the remote key for 500 milliseconds.

The third way is to press the inner button located by the driver's seat, which also has to be held in for 500 milliseconds.

By quickly pressing in switch handle quickly twice the function is deactivated for Power Operated Tailgate Module (POT), and the tailgate can then be opened manually.

The tailgate can only be opened if the vehicle's speed is below 1 km/h. If the speed exceeds 1 km/h after an opening phase has been started, the tailgate will stop and be disengaged.

There is only one way of closing the tailgate electrically, and this is with the switch on the lower edge of the tailgate. If the vehicle's speed exceeds 1 km/h after an closing phase has been started, the tailgate will continue to close.

The Power Operated Tailgate Module (POT) can open and close the tailgate at temperatures between -30 °C and +70 °C.

Learning top position 

The Power Operated Tailgate Module (POT) can be taught a maximum opening angle (top position). This is done, when the lid is in the desired top position, by pressing the switch on the lower edge of the lid for longer than 3 seconds. If the lid is moving when the switch is pressed, motion stops.

Minimum possible value of learned (maximum) opening angle is 30 degrees, calculated from closed lid (corresponds to 260 hall pulses). The lid can, however, be opened a greater angle than the learned one manually.

Suspended functionality 

If the vehicle continues in ignition position III at the same time as automatic movement of the boot lid occurs, the lid stops. After moving from ignition position III, the lid continues.

There is a motor protection to prevent overheating of the boot lid opening motor and motor shutdown. The frequent use of automatic operation of the boot lid can cause the Power Operated Tailgate Module (POT) to temporarily disable its functionality. If overheating occurs during a closing phase, closing the boot lid is completed and then the boot lid can only be opened manually. The overheating function is controlled by a counter. If the boot lid opening/closing motors are active, the counter increases and when these motors are not active the counter decreases. The overheating function becomes active when the counter has reached a specific maximum value. Automatic operation of the boot lid is again possible after a certain time interval, while it is off it is still possible to open and close the boot lid manually

Under DIAGNOSTICS/VEHICLE COMMUNICATION/POT/Parameters it is possible to read out parameters that indicate the last cause for interrupted tailgate opening, not approved opening/closing, and reasons why the lid has opened. 

System structure 

The automatic operation is driven by two electric motors controlled by a separate PWM signal each from the Power Operated Tailgate Module (POT). The boot lid position is determined by hall sensors. The left boot lid opening/closing motor is equipped with 2 hall sensors and the right boot lid opening/closing motor is equipped with 1 hall sensor. The motors are located in the left or right side of the boot lid, in the vertical gutter. The motor's motion forces a rod to move, and this movement affects the tailgate via the extension of the rod. The Power Operated Tailgate Module (POT) is connected to one closing boot lid motor, two boot lid opening/closing motors, one closing button and a switch handle for opening the boot lid. The Power Operated Tailgate Module (POT) controls the functionality of the boot lid closing motor and the boot lid opening/closing motors. The boot lid opening function is controlled by the central control module (CCM).

Opening 

The Central electronic module (CEM) disengages the lock that release the boot lid, then the Power Operated Tailgate Module (POT) opens the boot lid using the boot lid opening/closing motors.

Closing 

The tailgate has two different closing sequences depending on whether the doors and windows are closed or open. When closing the tailgate when all doors and windows are closed, air resistance is relatively large. The tailgate is then likely to reach the outer locking position. A motor helps to pull the tailgate closed the last part to the inner locking position with the aid of a wire. When the tailgate reaches the inner locking position the motor reverses to reset the cable's position to the starting position and thus enable a new closure. If the tailgate does not reach the inner locking position within three seconds, a time-out occurs because the motor still reverses back. In order for the tailgate control module to determine when it is time to end the motor reversal, there is a sensor in the motor that gives a feedback signal stating whether the motor has reversed or not.

When closing the tailgate when all doors and windows are open, air resistance is relatively small. The tailgate is then likely to reach the inner locking position without the assistance of motor closure.

For further information, also see appropriate Design and Function information for the Central locking.

The system is transparent in the sense that the tailgate can be operated manually by a double press of the switch handle on the tailgate if the Power Operated Tailgate Module (POT) is powered or if the function is not enabled.

The system is equipped with a safety function that prevents the boot lid from falling quickly. This is to prevent personal injury and damage to objects, which can occur if the gas struts do not function as expected.

If something were to obstruct the tailgate during the closing phase, the tailgate immediately stops and reverses 5-10 °.

If something were to obstruct the tailgate during the opening phase, the tailgate stops and maintains its position.