Windows: Description and Operation

CIRCUIT OPERATION

A permanent magnet (PM) Motor operates each of the Power Windows. Each Motor raises or lowers the glass when voltage is supplied to it. The direction the Motor turns depends on the polarity of the supply voltage.


The Power Window Master Switch Assembly controls all of the Motors and the Express Down Window Module. Each Window Switch controls only one of the Motors.


Master Switch Assembly Operation

When the Ignition Switch is in RUN, battery voltage is applied to the Master Switch Assembly through the PNK wire.

When any of the UP switches in the Power Window Master Switch Assembly not associated with Express Down are operated, battery voltage is applied to the Window Motor. The Window Motor is grounded through the DN contact in the Power Window Master Switch Assembly. The Motor runs to drive the window up. When any of the DN Switches in the Power Window Master Switch Assembly are operated, battery voltage is applied to the Window Motor in the opposite direction. The Window Motor is grounded through the UP contact in the Power Window Master Switch Assembly. The Motor runs to drive the window down.


Express Down Window Operation

The Express Down Window function is a convenience feature that allows the LH front window to be fully opened by holding the LH Front Window Switch DOWN for more than 0.3 seconds then releasing. If the LH Front Window Switch is held DOWN for less than 0.3 seconds, the window will only move down a small distance.


When the ignition is in RUN, the Express Down Window Module receives power at terminal A. When the LH Front Window Switch is held DOWN for more than 0.3 seconds and released, the Timer and Control Unit detects this at the down input terminal. The Relay Control Switch closes, completing the coil circuit through the LH UP Switch in the Power Window Master Switch Assembly to ground G306. The relay contacts close and the LH Window Motor receives battery voltage.

Terminal B of the motor is grounded through the Master Switch Assembly LH UP contact. When the window is fully down the motor stall current will be detected at the current sense input of the Timer and Control Unit. The Relay Control Switch will be opened, de-energizing the coil and disconnecting power to the motor. The motor will also be stopped 20 + 10 seconds after the DN Switch is pushed.


If the LH Front UP or DN Switch is pushed while operating in the Express Down mode, the Timer and Control Unit will detect this and open the Relay Control Switch. The window will stop moving down. If the power input at terminal A of the Express Down Module is lost, the power window will still operate but without the Express Down feature.