Power Operated Tailgate Module (Pot), Structure Week 201046- [2011]: Function: Tailgate
Risk of component damage Open, or close, the tailgate slowly if the battery is disconnected. The spindle motors can be damaged if these instructions are not followed. The entire movement must take longer than 5 seconds.
If the vehicle is not equipped with the keyless entry system the remote receiver module (RRX) communicates directly with the Central electronic module (CEM). If the vehicle is equipped with the keyless entry system, the remote keyless entry (RKE) communicates via the Keyless vehicle module (KVM).
There are three ways of opening the tailgate. The usual 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 the button on the remote key for 500 milliseconds. The third way is to press the button inside by the driver's seat, this must also be depressed for 500 milliseconds.
By pressing the switch handle twice quickly, the opening Power Operated Tailgate Module (POT) function is deactivated, and the boot lid can then be opened manually. The door can be opened only if the vehicle speed is less than 1 km/h. Should the speed exceed 1 km/h after an opening phase has begun, the lid will stop and release.
There is only one way of closing the tailgate electrically and that is with the switch on the lower edge of the tailgate. If the vehicle's speed exceeds 1 km/h after a closing phase has been started, the tailgate will continue to close.
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 motor protection to prevent overheating of the boot lid opening motor and motor shutdown. In the event of frequent use of automatic control of the boot lid, the Power Operated Tailgate Module (POT) can choose to temporarily disable its functionality. Automatic operation of the boot lid will be available after a certain time interval; during the time it is off it is still possible to open and close the 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
Automatic operation is driven by an electric motor controlled by a PWM signal from the Power Operated Tailgate Module (POT). The motor's movement forces a piston to move, and this movement acts on the tailgate via the piston rod's extension. Two gas springs also assist the opening of the tailgate. Two hall sensors, located in an electric motor, communicates its motion to the Power Operated Tailgate Module (POT).
Opening
The Central electronic module (CEM) disengages the catch that release the boot lid, then the Power Operated Tailgate Module (POT) opens the boot lid using the boot lid opening/closing motor and gas struts.
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 Design and Function, Central locking.
The boot lid can be operated manually even if the vehicle is not powered or if the function is not activated.
The system is equipped with a safety function that prevents the tailgate 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.