Windows: Description and Operation

CIRCUIT OPERATION:
A permanent magnet (PM) motor operates each power window. The direction the motor turns depends on the supply voltage polarity. Each motor is protected by an electronic circuit breaker. If a window switch is held too long with the window obstructed, or after the window is fully up or down, the circuit breaker opens the circuit. The circuit breaker has a positive temperature coefficient and resets automatically when voltage is removed from the motor.

Express Down Window Operation
The express down window function is a convenience feature that allows the LH front window to be fully opened when the LH front window DN switch is operated for more than 0.3 seconds. If the LH front window DN switch is operated for less than 0.3 seconds, the window only moves down a small distance.

When the ignition switch is in RUN, the express down window module receives power at terminal A. When the LH front window DN switch is operated for more than 0.3 seconds, the timer and control unit detects this at the down input terminal. The relay control switch closes, completing the coil circuit through the LH (front window) UP switch in the LH master switch assembly to ground. The relay contacts close and the LH front window motor receives battery voltage. Terminal B of the motor is grounded through the LH master switch assembly LH (front window) UP switch contact. When the window is fully down, the motor stall current is detected at the timer and control unit's current sense input. The relay control switch opens, de-energizing the coil and disconnecting power to the motor. The motor is also stopped 20+/-10 seconds after the LH front window DN switch is pushed.

If the LH front window UP switch is pushed while operating in the express down mode, the timer and control unit detects this at the UP input terminal and opens the relay control switch. Ground is removed from the LH front window motor terminal B. The window stops moving down and moves up if the UP switch is held. If the power input at express down module terminal A is lost, the power window still operates, but without the express down feature.