Windows: Description and Operation

GLASS, FRAMES AND MECHANISMS

The glass, frames and mechanisms include the window control switches, door window motor(s), door window regulator(s), window glass, rear window glass and the windshield glass.

One-Touch Down Window
The one-touch down feature can be activated by pressing the LH window control switch to the second down position. This allows the LH door window glass to move downward until it is fully lowered. Momentarily pressing the window control switch while the window is moving downward will stop the door window glass and restore proportional down operation. This feature is only on the LH window.

Door Window Glass
The bottom of the door window glass is mounted on a slider bracket which is part of the door window regulator. Door window glass bracket spacers provide attachment points for the door window glass and prevent direct contact between the slider bracket and the door window glass.

Short Drop Driver and Passenger Windows
The short drop driver and passenger window feature determines when to carry out a driver or passenger window short drop command, in order to drop or close a single window or both windows when a door is ajar or the convertible top switch is activated. When the driver or passenger door is ajar, the appropriate window will drop. After the open door is closed, the window will then close. If the convertible top switch is activated, causing the windows to drop, both windows will close if the PRNDL is taken out of PARK or if one door becomes closed. If the FEM/REM have been entered into the diagnostic mode while the windows are dropped, the windows will need to be manually raised by using the window control switches. Calibration of the short drop feature will not be affected.

Window Control Switch
The LH window control switch can be used to power either or both of the windows. A window control switch is located on the RH door armrest to activate the RH window only. The LH window control switch sends a voltage signal to the FEM for the operation of the LH window motor and sends a voltage signal to the REM for the operation of the RH window motor. The RH window switch sends a voltage signal to the REM for the operation of the RH window motor.

Window Motor
Window motors are installed separately. The one-touch down feature is not controlled by the window motor, but by the window control switch and the FEM.

RH Window Power Supply
The REM controls the power supply to the RH power window motor. To protect the REM from a potential failure, the REM removes power from the RH window power supply when a short to ground is sensed in the RH window control switch, associated circuitry or the power output circuit of the REM. Power is restored to the power output circuit upon a cycling of the ignition switch. If the REM output circuit is shorted to ground, the REM immediately removes power from the power supply circuit. If the RH window control switch or the associated circuits are shorted to ground, the power will remain on the REM output circuit until the switch or circuit containing the short to ground is activated.

Heated Rear Window
The heated rear window is controlled by the REM and the dual automatic temperature control (DATC) modules. The heated rear window switch is incorporated into the DATC module. When the switch is pressed ON, the DATC module sends a message over the SCP network to the REM. The REM then grounds the heated rear window relay coil circuit (which is hardwired to the REM). The ground signal closes the heated rear window relay which applies power to the heated rear window grid. Fault management of the heated rear window feature prevents the heated rear window from operating when an ignition switch invalid/missing data message is received. The heated rear window eliminates condensation on the rear window.

Delayed Accessory
The delayed accessory feature allows the power windows and radio to function for up to 10 minutes after the ignition switch is turned OFF, or until either door is opened. The delayed accessory function is controlled by the REM. When the ignition switch is turned from ON to OFF, the REM begins the timing sequence. If a door is opened, the REM will turn off the delayed accessory function. If the ignition switch is turned to another position, the REM will also cancel the delayed accessory function.

Front Electronic Module (FEM) and Rear Electronic Module (REM)
The FEM receives inputs and delivers outputs to a majority of the electronically controlled features which reside primarily in the front of the vehicle, including the LH power window. The REM receives inputs and delivers outputs to a majority of the electronically controlled features which reside primarily in the rear of the vehicle, including the RH power window. The FEM and the REM are configurable modules and must be correctly configured to the vehicle. The modules may also be configured to allow features or functions to be added to the vehicle. The FEM and the REM do not have any optional window control configurations.

Module Inputs and Outputs
The FEM and the REM input/output systems are unique in that many inputs the are received over the SCP communication network. These input messages come from other modules connected to the network. The FEM and the REM interpret the inputs, then command the correct output that was requested. The modules also receive inputs which come from components directly hardwired to the modules, such as the window control switches.

One type of output the modules provide is over the SCP communication network in the form of messages. These types of outputs are usually generated from a module monitoring a hardwired input and sending a status message to another module. These outputs are commonly required by other modules to carry out their functions. The second type of output is the control of a component directly hardwired to the module.