TrailBlazer 2WD V8-6.0L VIN H (2006)
Vanity Lamp: Description and Operation
VANITY MIRROR LAMPS
The inadvertent power courtesy lamps supply voltage circuit of the body control module (BCM) provides battery positive voltage to each vanity mirror
lamp. When the vanity mirror cover on the sunshade is opened, a switch closes to provide a ground circuit and the vanity lamp illuminates.
Battery Rundown Protection/Inadvertent Power
The body control module (BCM) inadvertent power courtesy lamps supply voltage circuit provides battery positive voltage to all of the interior reading
lamps and both visor vanity mirror lamps. In the event that any of these lamps were to remain illuminated for a period of more than 20 minutes with the
ignition switch in the OFF position, the BCM will deactivate the inadvertent power courtesy lamps supply voltage circuit to prevent a total battery
discharge condition. Only when the ignition switch is cycled back to the RUN position will the BCM reset the internal timer and reactivate the
inadvertent power courtesy lamps supply voltage circuit.
The BCM also utilizes the inadvertent power courtesy lamps supply voltage circuit as a courtesy lamp request signal circuit when none of the lamps in
the circuit are illuminated. When a lamp switch is activated, the BCM receives the request for lamp illumination and switches to supplying voltage to the
inadvertent power courtesy lamps supply voltage circuit.
