Land Rover Discovery: Glass, Frames and Mechanisms - Operation

DOOR GLASS

The door glass operates with the ignition in either accessory or on mode and, after the ignition is switched off, for 5 minutes or until a door is opened.

When a window open or close selection is made on a door switchpack, the related door module supplies power to the window motor to drive it in the appropriate direction. In the inch mode, the motor stops when the switch is released or the window reaches the end of its travel. In the one-shot mode, the motor stops if the switch is operated again (either up or down) or the window reaches the end of its travel One-shot up operation causes a door window to fully close unless an object is detected (anti-trap). If the anti-trap algorithm detects an object, the glass will drop fully open or to 200 mm below the obstruction.

When the passenger door switchpacks are used, they produces an open or close request by completing a hard wired circuit with the PDM.

When the driver door switchpack is used, it outputs a request message to the DDM on the LIN bus. If the message is for one of the passenger doors, the DDM relays the message to the relevant door module on the MS CAN body bus.

If one of the passenger doors glass has opposing up and down requests from one of the passenger door switchpacks and the driver door switchpack, operation of the door glass will cease until one of the switches is released

GLOBAL OPENING AND CLOSING

If the Smartkey unlock or lock switch is pressed and held for 3 seconds, in addition to unlocking or locking the vehicle and disarming or arming the alarm, the door glass of all doors will open or close.

Global opening and closing requests from the Smartkey are detected by the Radio Frequency (RF) receiver and verified by the Keyless Vehicle Module (KVM). The CJB then sends the request to the door modules on the MS CAN body bus.

ONE-SHOT WINDOW OPERATION RESET

If the battery is disconnected, the window lift system will require calibrating on battery re-connection. To calibrate the system the following routine must be carried out.

With the ignition in power mode 6:

• Fully close the door glass and release the switch.
• Re-apply the switch to close the door glass and hold for approximately 2 seconds.
• Fully open the door glass and release the switch.
• Re-apply the switch to open the door glass and hold for approximately 2 seconds.
• Repeat for all remaining windows.

ANTI-TRAP PROTECTION

The anti-trap feature is incorporated for the door glass in both the inching and one-shot modes. If the anti-trap function is activated while a window is closing, the window will reverse by approximately 200 mm Each window motor has two Hall sensors to enable the related door module to monitor the motor speed. If the motor speed decreases below a set threshold, indicating an obstruction, the power feed to the motor is reversed so the window goes back down.

If it is still necessary to raise the window, the anti-trap protection can be overridden by attempting to close the window at intervals of less than 10 seconds. On the third attempt the window will move up with anti-trap protection disabled to overcome the obstruction.

HEATED REAR WINDOW

Heated rear window operation is only enabled when the engine is running.

The ATCM controls operation of the heated rear window using a relay in the CJB. When a request is made for heated rear window operation, the ATCM broadcasts a message to the Gateway Module (GWM) on the MS CAN comfort bus, the GWM then relays this message on to the CJB using the MS CAN body bus. On receipt of this message, the CJB energizes the relay by providing a ground path for the relay coil. This allows a battery feed to flow across the relay to power the heater element.

There are 2 modes of heated rear window operation; manual and automatic.

Manual operation is activated by pressing the heated rear window switch.

When the switch is pressed, the status Light Emitting Diode (LED) in the switch illuminates and the rear window heater element is energized. Manual operation is discontinued when the heated rear window switch is pressed a second time, between 5 and 21 minutes have elapsed (dependent on ambient air temperature), or the engine stops. If manual operation is discontinued by the engine stopping, the previous heating phase is resumed if the engine is re-started within 30 seconds.

There are 2 variants of automatic operation; automatic operation at the start of a journey and automatic operation during a journey.

Automatic operation at the start of a journey is initiated for between 5 and 21 minutes (dependent on ambient air temperature). The warmer the ambient air temperature, the shorter the time. In this instance, the switch LED is illuminated and the heater element is energized. In addition to shorter operating times in temperate winter conditions, there are condition qualifiers to prevent subsequent operations once the cabin or engine is warm, or there is a significant sunload. Automatic operation is discontinued if the heated rear window switch is pressed or the engine stops

NOTE:

This feature can be selected on and off on the Settings page of the Climate menu in the touch screen.

Automatic operation during a journey is initiated when low ambient air temperatures are experienced and the vehicle has been traveling for a set period of time above a threshold speed. In this instance, no feedback is given to inform the driver that the heated rear window is operational (the switch LED is not illuminated) and the duration of operation is variable depending upon the ambient air temperature, vehicle speed and the amount of time the vehicle has been travelling.

HEATED WINDSHIELD (WHERE FITTED)

Heated windshield operation is only enabled when the engine is running.

The ATCM controls operation of the heated windshield using a relay in the Battery Junction Box (BJB). When a request is made for heated windshield operation, the ATCM broadcasts a message to the GWM on the MS CAN comfort bus, the GWM then relays this message on to the CJB using the MS CAN body bus. On receipt of the message, the CJB energizes the relay by providing a ground path for the relay coil. This allows a battery feed to flow across the relay to power the left and right heater elements.

There are 2 modes of heated windshield operation; manual and automatic.

Manual operation is activated by pressing the heated windshield switch.

When the switch is pressed, the status LED in the switch illuminates and the windshield heater elements are energized. Manual operation is discontinued when the heated windshield switch is pressed a second time, between 2 and 5 minutes have elapsed (dependent on ambient air temperature), or the engine stops. If manual operation is discontinued by the engine stopping, the previous heating phase is resumed if the engine is re-started within 30 seconds.

There are 2 variants of automatic operation; automatic operation at the start of a journey and automatic operation during a journey.

Automatic operation at the start of a journey is initiated for between 2 and 5 minutes have elapsed (dependent on ambient air temperature). The warmer the ambient air temperature, the shorter the time. In this instance, the switch LED is illuminated and the heater elements are energized. In addition to shorter operating times in temperate winter conditions, there are condition qualifiers to prevent subsequent operations once the cabin, engine or screen is warm, or there is a significant sunload. Automatic operation is discontinued if the heated windshield switch is pressed or the engine stops.

NOTE:

This feature can be selected on and off on the Settings page of the Climate menu in the touch screen.

Automatic operation during a journey is initiated when low ambient air temperatures are experienced and the vehicle has been traveling for a set period of time above a threshold speed. In this instance, no feedback is given to inform the driver that the heated windshield is operational (the switch LED is not illuminated) and the duration of operation is variable depending upon the ambient air temperature, vehicle speed and the amount of time the vehicle has been travelling.

INPUT/OUTPUT DIAGRAM - DOOR GLASS

A = HARDWIRED CONNECTION; AO = MEDIUM SPEED CAN BODY BUS; O = LIN BUS.

1. DDM
2. PDM
3. Right rear door module
4. Left rear door module
5. CJB
6. KVM
7. Ground
8. Power feed
9. Left rear window motor
10. Left rear window switchpack
11. Right rear window motor
12. Right rear window switchpack
13. Passenger window motor
14. Passenger window switchpack
15. Driver window motor
16. Driver window switchpack

INPUT/OUTPUT DIAGRAM - HEATED REAR WINDOW AND WINDSHIELD HEATER

A = HARDWIRED CONNECTION; AO = MEDIUM SPEED CAN BODY BUS; AP = MEDIUM SPEED CAN COMFORT BUS

1. CJB
2. GWM
3. ATCM
4. BJB
5. Windshield heater elements
6. Rear window heater element
7. Ground
8. Power feed

Glass, Frames and Mechanisms - DescriptionGlass, Frames and Mechanisms / Diagnosis and Testing

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