Sunroof / Moonroof: Description and Operation

Roof Opening Panel

COMPONENT LOCATION









OVERVIEW
The roof opening panel is a double length glass unit, with the rear half being fixed in position.
The front half of the roof opening panel is electrically operated through a 2 way rocker switch located in the roof console. An electric motor, attached to the rear of the roof opening panel frame, drives the front glass panel to the tilt, open or closed position. The glass panel is operated by 2 cables, which are driven by the motor.
Operation of the roof opening panel is controlled by the roof opening panel control unit, which is integral with the motor. The control unit receives inputs from the CJB and the switch to control roof opening panel operation accordingly. The CJB also provides a vehicle speed signal to the control unit, which is used to calibrate the anti-trap feature.

CONTROL UNIT/MOTOR









The combined control unit and motor assembly is mounted behind the headlining, to the rear of the roof opening panel. The control unit uses inputs from the CJB and the roof opening panel switch to control operation of the motor.
The end of the motor armature is formed as a worm drive, which drives a gear attached to the end of the motor assembly. The gear engages with helixed cables in the roof opening panel frame to form a rack and pinion drive.
The control unit incorporates a Hall effect sensor which is used to count the revolutions made by the motor armature. By counting the revolutions the control unit can accurately determine when the glass panel has reached its fully open, closed or tilt position by comparing the armature rotation value against values stored in its memory. The values are stored in the control unit's memory when the initialization routine has been carried out.
The control unit also monitors the temperature of the motor and will suspend operation if an overheat situation is likely to occur. The thermal protection function has 2 levels of operation.
- Level 1 - The control unit will only allow the roof opening panel to be closed
- Level 2 - All operation is suspended except 'Anti-Trap'.

ROOF OPENING PANEL









The roof opening panel is attached to the outside of the body side panels, the front roof panel and the rear roof panel with a Polyurethane (PU) adhesive. The roof panel comprises a plastic one piece frame housing 2 glass panels.
The rear glass panel is fixed in position and bonded to the roof opening panel frame using a PU adhesive. The forward glass panel is driven into position by a pair of helixed cables. The helixed cables are able to push or pull the forward glass panel into the required position.
The roof opening panel also contains 2 integral, manually operated sunblinds and 2 drain hoses. The drain hoses are connected to the center of the frame above the B pillars. The drain hoses run through the cant rails and down the C pillars to allow water collected in the frame to escape.

CONTROL DIAGRAM

NOTE:
A = Hardwired; D = High speed Controller Area Network (CAN) bus









PRINCIPLES OF OPERATION
The roof opening panel will only operate when the vehicle is in power mode 6 (ignition on). Power is supplied to the roof opening panel control unit/motor by the CJB, which supplies both a permanent battery and ignition power supply. The CJB also provides a vehicle speed signal to the control unit.
For details on how to operate the roof opening panel, refer to the 'Owners Handbook'.

Switch Inputs
The roof opening panel rocker switch is mounted in the roof console and is provided 2 signal feeds by the control unit. When the switch is in the rest (central) position, both connections from the control unit are open circuit. When the switch is pressed to open the glass panel, the signal feed from pin 4 of the control unit electrical connector is provided a ground path through the switch contacts. When the switch is pressed to close the glass panel, the switch grounds the signal feed from pin 8 of the control unit electrical connector.
When tilt operation is requested, the switch grounds the signal feed from pin 8 of the control unit electrical connector as described for 'close' operation.

Anti-Trap
The roof opening panel motor is calibrated to detect a blockage that will prevent the glass panel from closing. The force required to close the glass panel on a stationary vehicle will not exceed approximately 100 Newtons (N). If this limit is reached, the control unit will power the motor in the opposite direction to reverse the position of the glass panel by 200 mm.
The control unit also monitors external forces which may increase the force required to close the glass panel. The control unit bases this figure on vehicle speed, rough road conditions, and extreme ambient air temperatures and may increase the maximum force applied by the motor to approximately 150 N if required.

Vehicle Speed Signal
The vehicle speed signal is used by the roof opening panel control unit to adjust the sensitivity of the anti-trap feature. This signal allows the control unit to take into account wind resistance when closing the roof opening panel at vehicle speeds higher than 2.5 mph (4 kph).
The vehicle speed signal originates in the ABS module, and is broadcast over the high speed CAN bus. The CJB converts the vehicle speed signal into a pulsed voltage signal for delivery to the control unit. This signal pulses at a rate of 8,000 pulses per mile (5,000 pulses per kilometer), and has a duty cycle of 50% on 50% off.

Calibration
If the battery is disconnected, or the power supply is interrupted, whilst the sunroof is partially open it will need to be recalibrated.
Once the battery is reconnected, or the power supply is restored, recalibrate the sunroof as follows:
- Switch the ignition on.
- With the sunroof closed, press and release the front of the switch. The sunroof will move to the tilted position ready for calibration.
- Press the front of the sunroof switch, and hold for twenty seconds.
- After twenty seconds the sunroof will begin to move. Keep the front of the switch pressed until the sunroof has fully opened, then closed.
- Once the open/close cycle has completed and the sunroof has stopped moving, release the switch.
The sunroof can now be operated as normal.