Ford Mustang (1999-2004) Service Manual: Principles of Operation

Power Window Control

NOTE: Battery power and ground must be removed before disconnecting the GEM connectors to avoid setting false DTCs.

The driver power window one-touch down operation is controlled by the generic electronic module (GEM). This feature functions only when the ignition switch is in the RUN or ACCY positions. The GEM determines ignition switch position by monitoring the key-in ignition, RUN/ACCY and RUN/START circuits. The one-touch down operation is requested of the GEM by momentarily pressing the driver window regulator control switch DOWN for 62 ms to 320 ms. The GEM uses the initial voltage input from the down switch to begin the one-touch down operation. If the voltage input was less than 320 ms, the GEM will maintain the voltage supply to the motor down circuit. The GEM will maintain the operation until:

• seven seconds expires.
• motor stall is detected by monitoring the current draw.
• a voltage input is received by the GEM on either the up or down switch circuits.

The ground for one-touch down operation does not pass through the GEM. The ground is supplied through the driver window regulator control switch as with normal operation. If the GEM continues to see voltage on the down circuit for more than 320 ms after initial activation the GEM will not effect operation. The down circuit through the GEM is a direct connection to the motor in its normal state.

This allows the driver window regulator control switch to control the motor for normal operation.

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