Principles of Operation

PRINCIPLES OF OPERATION

LH and RH Front Power Window Control - Zephyr
The LH and RH front window motors contain integral electronics which must be initialized whenever a new window motor has been installed. 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 switch in the RUN or ACCESSORY positions, or when the delayed accessory 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 will 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 will automatically reverse direction and move the glass toward the fully OPEN position (in both proportional 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 will move 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 will stop with bounce-back automatically enabled for the next window up movement. If the ignition switch is turned to OFF or START (without delayed accessory), the window motor will stop. 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 will bounce back, then stop. Ice, contaminant buildup and environmentally induced tight spots in the front window seals are all possible conditions that will activate the security override feature. If an obstruction occurs between 4 mm (0.15 in) and 200 mm (7.87 in) of window opening, the bounce-back position will be 250 mm (9.84 in) of window opening. If an obstruction occurs at a position greater than 200 mm (7.87 in) of window opening, the bounce-back position will be 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 are used to 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 will not function. If the main ground signal is missing, the AUTO functions will be inoperative and the window will also be inoperative.

If there is an open in the LH or RH front window control switch or the associated wiring, the related function will become inoperative. If the UP contact of the switch or the associated wiring develops an open circuit, the front window will only operate 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 will only operate 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 will only move proportionally UP or DOWN.

A new LH or RH front window motor will only operate in proportional up/down mode, and the bounce back feature will be disabled prior to initialization. If the switch is actuated to the AUTO up or AUTO down position and released, window movement will stop 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 Door Window Motor Initialization. Testing and Inspection

The LH and RH front window motors will automatically adjust to system changes throughout its life: changes in seal drag and slight changes in the full OPEN position will occur and will be automatically compensated for. Once initialized, the front window motors will soft stall into the UPPER and LOWER positions contributing to extended durability of the system. 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 will be energized for a fraction of a second to fully seal and this new position will be learned.

LH Front Power Window Control - Fusion and Milan
The one-touch down feature is controlled by the driver window control switch.

Passenger Window Operation
Passenger windows may be raised or lowered using the LH front window control switch or the corresponding passenger window control switch. Passenger window control switches receive power when the delayed accessory 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 passenger windows will not operate.

Delayed Accessory Power
The smart junction box (SJB) controls power to the power windows, the audio system and the power roof opening panel with the delayed accessory relay. The SJB activates the delayed accessory relay whenever the ignition switch is in the RUN or the ACCESSORY position, or when the ignition switch is changed from RUN or ACCESSORY to the OFF/LOCK position and the LH and RH front doors are closed.

The SJB will deactivate the delayed accessory feature when:
- the LF door is ajar and the ignition switch is in the OFF/LOCK or KEY-OUT position.
- the RF door is ajar and the ignition switch is in the OFF/LOCK or KEY-OUT position.
- ten minutes have elapsed since the ignition switch was changed from ACC or RUN to the OFF/LOCK position.

Rear Window Defrost
The smart junction box (SJB) controls power to the heated backlight by controlling the state of the heated backlight relay (integral to the SJB module). When the rear window defrost switch is pressed, the SJB will activate the heated backlight relay. When the heated backlight relay is active, the heated backlight will be energized.

The SJB will deactivate the heated backlight relay when one of the following conditions is met:
- The rear window defrost switch is pressed when the feature is active
- Ignition switch state is changed from RUN to OFF/LOCK
- The 17-minute timer completes