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Home >> Infiniti >> 2003 >> Q45 >> Repair and Diagnosis >> Body & Frame >> Windows >> Rear Window Defogger >> System Description
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System Description

The rear window defogger system is controlled by the BCM (Body Control Module), The rear window defogger is operated only for approximately 15 minutes. Power is supplied at all times

With the ignition switch in the ACC or ON position, power is supplied

With the ignition switch in the ON or START position, power is supplied

When the rear defogger switch in the multifunction switch is ON, ground is supplied

Then ground is supplied

Then BCM recognizes that rear window defogger switch is turned to ON. When BCM recognized that rear window defogger switch is turned to ON, ground is supplied

When rear window defogger and door mirror defogger relay is turned ON, power is supplied

Rear window defogger terminal 1 is ground through body ground B422.

With power and ground supplied rear window defogger filaments heat and defog the rear window.

When rear window defogger and door mirror defogger relay is turned ON, power is supplied.

Door mirror defogger relay terminal 1 is ground through body ground B17 and B57. With power and ground supplied,

Door mirror defogger relay is energized.

When door mirror defogger relay is turned ON, power is supplied.

Door mirror defogger (D and P) terminal 5 is ground through body grounds M24 and M114. With power and grounds supplied, door mirror defogger filaments heat and defog the mirror. When rear window defogger and door mirror defogger relay is turned ON, power is supplied.

Multifunction switch (rear window defogger switch) terminal 2 is ground through body ground M24 and M114. And then energizes rear window defogger indicator is illuminated.