Fixed and Moveable Windows
2-11
window to close. The return path to ground is supplied
through the inactive control circuit being normally
grounded through the window switch.
Each passenger and rear window switch
communicates to the BCM by a serial data circuit.
When the driver wishes to control the passenger, left
rear or right rear window, the driver will use the
appropriate switch on the driver window switch. When
this switch is used, a serial data message is sent to the
BCM requesting a window motor command, the BCM
will then send a serial data message to the appropriate
door window switch which will then command that
window to move in the direction requested.
Lockout Switch Feature
The driver window switch contains a window lockout
switch, when the driver presses the window lockout
switch, a serial data message is sent to the BCM which
will send a disable command to the rear window
switches, the rear window switches will then ignore all
functions when a passenger uses the rear window
switch. The rear window motor commands will still
function normally when the driver uses the appropriate
switches on the driver window switch.
Rear Window Defogger Description
and Operation
Rear Window Defogger System
Components
The rear window defogger system consists of the
following components:
•
HVAC Control Module
•
HVAC Controls
•
Rear Defogger Relay
•
Rear Defogger Grid
•
Driver Outside Rearview Mirror
•
Passenger Outside Rearview Mirror
•
40A Fuse
2021 - Silverado 4500HD, 5500HD, and 6500HD Electrical Body Builder Manual