Principles Of Operation

Glass, Frames and Mechanisms

Principles of Operation

Power Window Control

The driver power window one-touch down feature is controlled by the driver window control switch with integrated electronics. The one-touch down feature is requested by momentarily pressing the driver window down switch for 32 ms to 480 ms. The initial voltage input from the down switch starts the one-touch down operation. If the voltage input is less than 480 ms, the driver window control switch maintains the voltage supply to the window regulator motor down circuit. The Battery Junction Box (BJB) accessory delay relay supplies the voltage to the switch for one-touch down operation. The switch maintains the one-touch down operation until one of the following occur:

- Seven seconds expire
- The switch detects the motor is stalled by monitoring the current draw
- A voltage input is received by the switch on either the up or down switch circuits

There is only one ground for the switch and it is used for normal window operation and for one-touch down operation, making diagnostics simpler. If the ground is open, all window operations (one-touch and normal) are inoperative. The switch monitors the voltage on the down circuit for the driver window. If the switch continues to detect voltage on the down circuit for more than 480 ms after initial activation, the switch does not enable one-touch down operation. The down circuit through the switch is a direct connection to the motor in normal window operation mode. This allows the driver window switch to control the motor for normal operation.

The passenger window motors are hardwired directly to the window regulator control switches.

The window regulator motor has built-in circuit protection to prevent overheating due to excessive or repeated current draw.

If the window motor is cycled against significant resistance, the circuit protection function may be activated. This prevents operation of the window motor for several minutes.

Intermittent operation due to activation of the circuit protection is NOT a sign of window motor failure. Intermittent window operation is indicative of significant resistance to the movement of the glass or excessive duty cycle (repeated glass cycling). Significant resistance to window function may also be caused by extreme cold temperatures or build-up of frost or ice on the glass.

The glass cycle time from full down to full up should be less than 3.5 seconds at an ambient temperature of 22°C (72°F). Verification of glass cycle time MUST be conducted at or above this temperature.

Rear Window Defrost

The rear window defrost is controlled by the Driver Door Module (DDM). The ignition switch must be in RUN for the rear window defrost to operate. Pressing the rear window defrost switch grounds the input to the DDM. If the module detects the ignition switch in RUN, ground is supplied to the rear window defrost relay output. The rear window defrost relay coil is energized which closes the contacts and supplies voltage to the antenna module. The antenna module then supplies voltage and ground to the rear window defrost grid.