SWITCH-REAR WINDOW DEFOGGER
DESCRIPTION
The switch for the rear window defogger (EBL) system
(1) is located in the A/C-heater control (2) in the
instrument panel center bezel (3). When the rear win-
dow defogger switch is pressed to the On position a
request signal is sent to the cabin compartment node
(CCN), which sends a message to the totally inte-
grated power module (TIPM) to operate the EBL sys-
tem.
When the high side driver in the TIPM is energized,
current is directed to the rear defogger grid lines and
to the heated side view mirrors (when equipped). The
grid lines heat the glass to help clear the surface of
fog or frost.
OPERATION
An amber indicator will illuminate when the rear window defogger switch is activated. When activated, the switch
sends a request signal to the cabin compartment node (CCN), which sends a message to the totally integrated
power module (TIPM) to energize the internal EBL high side driver to provide battery current to the rear window
defogger grid lines and, when equipped, to the heated side view mirrors.
NOTE: The EBL system turns off automatically after 10 minutes of initial operation. Each following activa-
tion cycle of the EBL system will last 5 minutes.
The EBL system will be automatically turned off after an initial programmed time interval of about 10 minutes as
long as the ignition switch is the Run position. After the initial time interval has expired, if the rear window defogger
switch is turned on again during the same ignition cycle, the EBL system will automatically turn off after about 5
minutes. The EBL system will automatically shut off if the ignition switch is turned to any position other than Run, or
it can be turned off manually by pressing the rear window defogger switch a second time.
The rear window defogger switch is diagnosed using a scan tool (refer to 8G - Heated Glass Electrical Diagnostics
for more information).
The rear window defogger switch and the rear window defogger indicator cannot be repaired and, if faulty or dam-
aged, the A/C-heater control must be replaced (refer to 24 - HEATING & AIR CONDITIONING/CONTROLS/CON-
TROL-A/C HEATER - REMOVAL).
PM
HEATED GLASS - SERVICE INFORMATION
8G - 27