Chrysler Concorde 2004 Service Manual page 1661

LH
REAR WINDOW DEFOGGER
SWITCH
DESCRIPTION
The rear window defogger switch is integral to the
a/c heater control, which is located in the instrument
panel center bezel.
The rear window defogger switch and the rear win-
dow defogger switch LED indicator cannot be
repaired and, if faulty or damaged, the entire a/c
heater control must be replaced. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/CONTROLS/A/C
HEATER CONTROL - REMOVAL)
OPERATION
On Manual Temperature Control systems when the
rear window defogger
depressed, it provides a hard wired signal by momen-
tarily closing the rear window defogger switch sense
circuit which is monitored by the BCM. On Auto-
matic Temperature Control (ATC) systems, when the
defogger switch is depressed, the ATC head sends a
switch status message to the BCM over the Program-
mable Communications Interface (PCI) data bus net-
work. A Light Emitting Diode (LED) in the push
button for the rear window defogger switch illumi-
nates to indicate when the rear window defogger sys-
tem is turned on. Each time the BCM rear window
defogger timer and logic circuitry sees another
request, it toggles a control output to the rear win-
dow defogger relay. Energizing the rear window
defogger relay provides electrical current to the rear
window defogger grid and to the LED indicator in
the switch, which lights to indicate when the defog-
ger system is turned on. A dedicated fuse in the junc-
tion block protects the rear window defogger relay
output circuit to the LED indicator.
switch push button
DIAGNOSIS AND TESTING - REAR WINDOW
DEFOGGER SWITCH
For instructions on how to use the DRB III scan
tool or the a/c heater control self-diagnostics to test
the control, (Refer to 24 - HEATING & AIR CONDI-
TIONING - DIAGNOSIS AND TESTING - SELF
DIAGNOSTICS). The problem is not with the a/c
heater control if no trouble codes are found. The next
step should be to check the rest of the system after
the MTC or ATC head is checked.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
is
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(Refer to 24 - HEATING & AIR CONDITIONING/
CONTROLS/A/C HEATER CONTROL - REMOVAL)
HEATED GLASS 8G - 7