Roof Opening Panel Motor

WARNING: This page is about a different car, the 2019 Land Rover Range Rover Velar. However, it is still accessible from the selected car via links, so may be relevant.

The opening and closing function of the roof opening panel and the roller-blind are controlled by a switch located in the front overhead console.

The roof opening panel motor uses a drive gear which engages and drives two cables within a sleeved tube. Each cable is linked to the open and close mechanism of the roof opening panel located either side of the panel in the guide rails. The rotation of the roof opening panel motor drives the cables in the required direction.

A position sensor is located in the motor which enables the Body Control Module/Gateway Module (BCM/GWM) assembly to calculate the exact position and operating speed of the roof opening panel. The position sensor is also an operational component of the anti-trap function.

The BCM/GWM assembly uses the operating speed of the roof opening panel and the current draw of the motor to detect an obstruction. If the roof opening panel closing speed decreases below a set threshold and the current draw from the motor increases, the power feed to the motor is reversed. This will then open the roof opening panel a set distance in the opposite direction of travel. In an emergency the anti-trap function can be overridden by holding the operating switch in the close position.

Depending on vehicle speed, the closing threshold of the anti-trap function is adjusted to counteract the force of air pressure acting upon the roof opening panel. Vehicle speed signal is transmitted from the Anti-lock Brake System (ABS) control module through the FlexRay bus to the BCM/GWM assembly. The BCM/GWM assembly processes and transmits the speed signal over a LIN bus connection to the roof opening motor. As vehicle speed increases, air pressure forces acting upon the sliding panel simultaneously increase, affecting the anti-trap functionality. The vehicle speed signal is used by the control module to re-calibrate the anti-trap algorithm, accounting for the extra force acting on the sliding panel. This function adapts the sliding panel closing speed threshold of the anti-trap function, dependent on vehicle speed.

The roof opening panel motor has a thermal protection device in the control module software to protect them from overheating.

The operating parameters are as follows:

If the temperature of the roof opening panel motor is above 120°C (248°F) the roof opening panel operation is restricted to a close only function.
If the temperature of the roof opening panel motor is above 120°C (248°F) when the roof is closed, movement will be inhibited.
If the anti-trap function is operational when closing, the reverse movement of the motor will complete its movement regardless of motor temperature.

Thermal protection for the roof opening panel motor and the roof opening panel blind motor are functioned simultaneously, therefore if one motor exceeds 120°C (248°F), the same restrictions, as defined above, will apply to both motors. For example, if the blind cannot be opened due to thermal protection, the roof opening panel will also ignore the opening command.