Principles Of Operation
Glass, Frames and Mechanisms
Principles of Operation
Delayed Accessory Power
The Body Control Module (BCM) controls voltage to the power windows, the audio system and the power roof opening panel (if equipped) with the accessory delay relay. The BCM (Body Control Module) activates the accessory delay relay whenever the ignition is in the RUN or the ACC position, or when the ignition is changed from RUN or ACC to the OFF position and the LH and RH front doors are closed.
The BCM (Body Control Module) deactivates the accessory delay relay when:
- the LH front door is ajar and the ignition is in the OFF or key-out position.
- the RH front door is ajar and the ignition is in the OFF or key-out position.
- ten minutes have elapsed since the ignition was changed from ACC or RUN to the OFF position.
LH and RH Front Power Window Control - MKX
The LH and RH front window motors contain integral electronics which must be initialized whenever a new window motor has been installed. Initialization is required to learn both the full UP and full DOWN positions and the profile of the glass as it travels through the glass channel. Once initialized, obstacle detection is enabled. When mechanical repairs have been carried out on either front window regulator or glass run, the applicable front window motor must be de-initialized, and then initialized. Both the LH and RH front window control switches send 3 separate signals to the front window motors: up, down and auto. The front window control switches provide a 12-volt signal to the front window motor to request an up or down operation. When auto up or auto down is requested, the front window control switches provide a 12-volt signal on the up or down line and a ground signal on the auto line simultaneously. The up, down and auto feeds to the front window motors are all low current.
The LH and RH front window motors operate with the ignition in the RUN or ACC positions, or when the accessory delay relay is active. The high current required to move the front windows are supplied through the B+ and motor ground input.
When the LH or RH front window motor is operating in auto up or auto down mode, movement of the front window can be stopped by pressing the switch to any position (UP, DOWN, auto UP, auto DOWN). The front window control switches must be released before the window can move again.
The LH and RH front window motors have a security override feature. If an obstacle has been detected in the window opening as the window glass is moving upward, the window motor automatically reverses direction and moves the glass toward the fully OPEN position (in both manual up and one-touch up modes). This is known as bounce-back. Once the window motor stops the glass at its bounce-back position, and within 2 seconds the switch is released, then held in the auto UP position, the window motor moves the glass up with no bounce-back protection (security override). If the switch is released before the window glass reaches the fully CLOSED position, the window motor stops with bounce-back automatically enabled for the next window up movement. If the ignition is turned to OFF or START (without delayed accessory), the window motor stops. The only exception is when an obstacle is detected in the window opening while delayed accessory power is not present. In this case the window motor bounces back, then stops. Ice, contaminant buildup and environmentally induced tight spots in the front window seals are all possible conditions that can activate the bounce-back feature. If an obstruction occurs between 4 mm (0.15 in) and 200 mm (7.87 in) of window opening, the bounce-back position is 250 mm (9.84 in) of window opening. If an obstruction occurs at a position more than 200 mm (7.87 in) of window opening, the bounce-back position is 50 mm (1.96 in) below where the obstruction occurred.
The LH and RH front window control switches have illumination and illumination ground inputs, which illuminate the switch when the headlamp switch is turned to the PARK or ON position (the AUTOLAMP position may also energize this input). These switch inputs do not directly affect operation of the front windows. The front window control switches use the delayed accessory power input, which is transferred to the up or down outputs when the corresponding switch contact is closed. The front window control switches are grounded to the chassis through the main switch ground input, which is transferred to the auto output when the corresponding front window control switch contact is closed. If the delayed accessory feed to the front window control switch is missing, the window cannot function. If the main ground signal is missing, the auto functions are inoperative and the window may also be inoperative.
If there is an open in the LH or RH front window control switch or the associated wiring, the related function becomes inoperative. If the up contact of the switch or the associated wiring develops an open circuit, the front window only operates in the down direction, or in the one-touch down mode. If the down contact of the switch or the associated wiring develops an open circuit, the window only operates in the up direction or in the one-touch up mode. If the auto contact of the switch or the associated wiring develops an open circuit, the window only moves manually up or down.
A new LH or RH front window motor cannot operate in one-touch up or one-touch down mode, and the bounce-back feature is disabled prior to initialization. If the switch is actuated to the auto UP or auto DOWN position and released, window movement stops when the up or down contact in the front window control switch is released. If the front window motor is removed from the window regulator drum housing, or if a new front window motor is installed, it must be initialized. Refer to Window Motor Initialization Procedures.
Once initialized, the front window motors soft stall into the lower positions. If the front window does not seal completely in the full UP position (very small gaps/non bounce-back events only), the front window switch can be actuated to the proportional UP position and the front window energizes for a fraction of a second to fully seal and this new position is learned.
LH Front Power Window Control - Edge
The one-touch up/down features are identical to the MKX LH front window.
Rear Passenger Window Operation
Rear passenger windows may be raised or lowered using the LH front window control switch or the corresponding passenger window control switch. The rear passenger window control switches receive voltage when the accessory delay relay is active and the LH front window lock switch is in the UNLOCK position. When the LH front window lock switch is in the LOCK position, the rear passenger windows cannot operate from the rear passenger window control switch.
Global Open - MKX only
NOTE: The global open feature may be enabled/disabled and in some cases modified through the message center.
When the unlock button of the Remote Keyless Entry (RKE) transmitter is held for 3 seconds, the global open activates. The BCM (Body Control Module) sends a signal to activate the one-touch down operation of both front windows and open the roof opening panel, if equipped. The global open feature does not operate if the accessory delay relay is active.
Rear Window Defrost
When the rear window defrost switch (integral to the Front Controls Interface Module (FCIM)) is pressed and the engine is running, the HVAC module activates the rear window defrost relay located in the Battery Junction Box (BJB). When the rear window defrost relay is active, the rear window defrost grid is energized.
If equipped, the rear window defrost can also be commanded on and off using voice commands or by touching the rear window defrost button located on the touchscreen interface. For additional information about voice or touchscreen commanded features, refer to the Owner's Literature.
The HVAC module deactivates the rear window defrost relay when one of the following conditions is met:
- The rear window defrost switch is pressed when the feature is active
- If equipped, the rear window defrost is commanded off using voice command or the touchscreen interface when the feature is active
- Ignition state is changed from RUN to OFF
- The 15-minute timer completes
Remote Start Climate Operation (if equipped)
The customer can select different climate control modes/preferences when the vehicle is started using the remote start feature. This can be accessed through the message center. For additional information on how to set the remote start preferences, refer to the Owner's Literature. When the rear defrost is set to AUTO mode, the rear window defrost activates when the outside temperature is less than 0°C (32°F) and the vehicle is started using the remote start feature. No climate control adjustments are recognized during remote start operation. Once the ignition is cycled to the ON position, the climate control system returns to the previous settings (last ignition ON cycle) and adjustments can be made normally. If the previous setting was off, the climate control system turns off.