Inspect and test the power window/lock control switch
Principles of Operation
Power Window Control
The driver power window one-touch down operation is controlled by the window/lock switch with integrated electronics. The one-touch down operation 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 was less than 480 ms, the window/lock switch will maintain the voltage supply to the window regulator motor down circuit. Central junction box (CJB) maxi-fuse 28 (20A) supplies the power to the switch for this operation. The switch will maintain the operation until:
seven seconds expire.
The switch detects the motor stalled by monitoring the current draw.
A voltage input is received by the switch on either the up or down switch circuits.
From the switch, there is only one ground that is used for normal window operation and for one-touch down operation, making diagnostics simpler. If this ground is open, all window operation (one-touch and normal) will be inoperative. The switch monitors 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 will not affect operation. The down circuit through the switch is a direct connection to the motor in its normal state. 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 will prevent 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. It 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.
Glass cycle time from full down to full up should be less than 3.5 seconds at an ambient temperature of 72 F (22 C). Verification of glass cycle time MUST be conducted at or above this temperature
Wednesday, June 8th, 2011 AT 10:32 PM