Windows: Description and Operation
Glass, Frames and Mechanisms
COMPONENT LOCATION
OVERVIEW
The laminated windshield is bonded and sealed to the body aperture using Polyurethane (PU) adhesive. Bonded to the inner surface of the windshield is the mounting boss for the interior mirror. Dependent on vehicle specification, the windshield may contain 2 heating elements between the windshield laminations.
The toughened rear screen is also bonded and sealed to the body aperture using PU adhesive. A single heating element is printed on the inner surface of the rear screen.
Operation of the window lift system is controlled by the CJB in conjunction with the driver door module and the front passenger door module. The door modules are mounted on the regulators of their respective front windows. Door modules are also mounted on both rear window regulators, and communicate with the front door modules over the Local Interconnect Network (LIN) bus.
The window lift system features one shot up and down operation, plus an anti-trap feature for all door windows.
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 on:
- 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.
DOOR MODULES
In addition to controlling the window lift system, the front door modules also control:
- Door locking. For additional information, refer to Handles, Locks, Latches and Entry Systems Description and Operation
- Door mirror adjustment and heating. For additional information, refer to Rear View Mirrors Description and Operation
For additional information, refer to Control Components Control Components
- Door mirror lamps. For additional information, refer to Interior Lighting Interior Lighting
The rear door modules control window lift and door locking only.
The door modules are color coded for position on the vehicle. The driver door module and both rear door modules are black. The passenger door module is gray. The electrical wiring harness connectors are also color coded to match the door modules.
NOTE:
Both rear door modules are identical.
If a front door module develops a fault, a Diagnostic Trouble Code (DTC) is stored in its memory. The DTC can be read using the Land Rover approved diagnostic system. If either of the rear door modules develop a fault, the DTC is stored in the respective front door module. For additional information, refer to Glass, Frames and Mechanisms Testing and Inspection
CONTROL DIAGRAM
NOTE:
A = Hardwired; N = Medium speed Controller Area Network (CAN) bus; O = LIN bus
PRINCIPLES OF OPERATION
The CJB provides a power supply to the driver door switch pack when the vehicle is in power mode 6 (ignition on). Switch requests made using the driver door switch pack are then delivered to the driver door module over the LIN bus.
The driver door module interprets the request made using the switch pack and responds as follows:
- If the request is for drivers side rear window operation, a request is transmitted over the LIN bus to the driver side rear door module.
- If the request is for front passenger window operation, a request is transmitted over the medium speed CAN bus to the passenger door module.
- If the request is for passenger side rear window operation, a request is transmitted over the medium speed CAN bus to the passenger door module. This request is then forwarded over the LIN bus to the passenger side rear door module.
Door Glass Opening and Closing
Each door module provides 2 signal feeds to its window lift switch. When a switch request is made, a ground path is created on one of the lines via the door module. From this the door module can determine which direction of travel has been requested.
The door modules power the door glass motors on receipt of a switch request or a request for Global Closing (see below). The door modules provide feed and return paths to their respective motor, which can switch depending on the direction of travel requested.
The door glass motor assemblies also contain a Hall effect sensor. The Hall effect sensor allows the door module to determine the position of the door glass and if a motor stall condition has taken place.
Global Closing
The AJB provides a constant battery feed to the 4 door modules. This feed is used operate the 'Global Closing' feature. Global Closing allows all 4 windows to be closed using the Radio Frequency (RF) handset.
NOTE:
The roof opening panel is not part of the Global Closing feature.
The Global Closing feature is activated by pressing and holding the 'lock' button on the RF handset for 3 seconds. The request for Global Closing is provided to the CJB by the RF receiver. The CJB then transmits this request to the driver and passenger door modules over the medium speed CAN bus.
Initialization
When the vehicle is delivered from the factory the window lift system will operate slowly until it has been initialized. The initialization process should be carried out using the Pre-Delivery Inspection (PDI) feature contained within the Land Rover approved diagnostic system. For more information, refer to the PDI manual.
Similarly, if a door module is replaced, the new module will require initialization before handover to the customer. The initialization process for a new module is carried out using the 'New Module' feature contained within the Land Rover approved diagnostic system.
NOTE:
If a driver door or passenger door module is replaced, both will require initialization. This ensures both front controlling modules contain the same level of software.