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8G - 10
HEATED SEAT SYSTEM
DRIVER HEATED SEAT
SWITCH
DESCRIPTION
The heated seat switch assemblies are mounted in
the left and right side front door trim panels. One
switch assembly is used for each front heated seat.
The two momentary position switches, are incorpo-
rated into one large switch assembly that also
includes other switches. The drivers side switch
assembly (Fig. 1) includes the memory, heat and
power seat switches as well as the adjustable foot
pedal switch. The passenger side switch assembly
includes the power seat and heated seat switches
only. The heated seat switches provide a resistive
multiplexed signal to the appropriate Door Module
through separate hard wired circuits. Each switch
has an Low and High position so that both the driver
and the front seat passenger can select a preferred
seat heating level. Each switch has two Light-Emit-
ting Diodes (LED) which light to indicate that the
heater for the seat is turned on.
Fig. 1 CS Driver Heated Seat Switch
1 - Switch Assembly
2 - Driver Heated Seat Switch
The heated seat switches and their LEDs cannot
be repaired. If either switch or LED is faulty or dam-
aged, the entire switch assembly must be replaced.
OPERATION
There are two momentary positions that can be
selected with each of the heated seat switches, Low
and High. When the left side of the switch rocker is
depressed, the Low position is selected and the low
position LED indicator illuminates. When the right
side of the switch rocker is depressed, the High posi-
tion is selected and the high position LED indicator
illuminates. If the switch is depressed a second time
in the same direction, Off is selected and both LED
indicators are extinguished.
Both heated seat switch assemblies provide sepa-
rate resistive multiplexed inputs to the appropriate
door module. The Door Module then sends a PCI
Data Bus message to the Memory Heated Seat
Adjustable Pedal Module (MHSAPM) to indicate the
selected switch position. The module responds to the
heated seat switch messages by controlling the 12v
output to the front seat heating elements. The Low
heat position set point is about 36° C (97° F), and the
High heat position set point is about 41° C (105° F).
DIAGNOSIS AND TESTING - DRIVER HEATED
SEAT SWITCH
For complete circuit diagrams, refer to Wiring.
CHECKING SWITCH SIGNAL AND WIRING AT THE
DOOR MODULE
(1) Disconnect and isolate the battery negative
cable.
(2) Access and disconnect the connector from the
driver door module. Visually inspect wiring terminals
for damage that would prevent positive connection. If
not OK, repair or replace the necessary components.
(3) Reconnect the negative battery cable and the
driver door module. Turn heated seat ON in the LO
position. Using an Ohmmeter, check the resistance
between the driver heated seat switch mux circuit
and fused ignition switch output circuit. Resistance
should be about 8 kiloohms (8020 ohms ±4%). If not
OK, check resistance directly at switch. If OK, go to
Step 4. If NOT OK replace the switch or faulty wir-
ing.
(4) Turn heated seat ON in the HI position. Using
an Ohmmeter, check the resistance between the
driver heated seat switch mux circuit and fused igni-
tion switch output circuit. Resistance should be about
2.4 kiloohms (2400 ohms ±4%). If not OK, check
resistance directly at switch. If OK, go to Step 5. If
NOT OK replace the switch or faulty wiring.
(5) With the system ON in the HI position, Check
for proper battery voltage and ground at the appro-
priate cavities. If OK, test heated seat element. If
NOT OK, repair open or wiring short.
CHECKING SWITCH ONLY
(1) The heated seat switch assembly used on CS
vehicles includes other switches. (Refer to 8 - ELEC-
CS
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