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CS
DRIVER HEATED SEAT SWITCH (Continued)
TRICAL/POWER SEATS/DRIVER SEAT SWITCH -
DIAGNOSIS AND TESTING)
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the front door trim panel. Refer to
Front Door Trim Panel Removal in the Body section
for the procedure.
(3) Disconnect the harness from the door module.
(4) Remove the heated seat switch assembly by
pressing in the four clips.
INSTALLATION
(1) Install the heated seat switch assembly.
(2) Connect the harness to the door module.
(3) Install the front door trim panel. Refer to the
Body section for the procedure.
(4) Reconnect the battery negative cable.
HEATED SEAT ELEMENTS
DESCRIPTION
The heated seat system utilizes two heated seat
elements in each seat, one for the seat cushion (Fig.
2) and the other for the seat back. Although two dif-
ferent heated seat systems are used for the front and
2nd row rear seats, the heated seat elements func-
tion the same way. The two elements for each 2nd
row rear seat are connected in series with the 2nd
row Heated Seat Module (HSM). The two elements
for each front seat are connected in parallel with the
Memory Heated Seat Adjustable Pedal Module
(MHSAPM). One temperature sensor is used for each
seat, and it is located in the seat cushion heated seat
element. The heated seat temperature sensor is a
Negative Temperature Coefficient (NTC) thermistor.
For more information on the heated seat sensor refer
to Heated Seat Sensor later in this section.
The heated seat elements are glued onto the seat
cushion and seat back cushion foam. The heated seat
elements and the temperature sensor cannot be
adjusted or repaired and, if faulty or damaged, the
heated seat element assembly must be replaced.
Refer to the procedure later in this section.
OPERATION
The heated seat elements resist the flow of electri-
cal current. When battery current is passed through
the elements, the energy lost by the resistance of the
elements is released in the form of heat.
The heated seat temperature sensor is a NTC ther-
mistor. When the temperature of the seat cushion
cover rises, the resistance of the sensor decreases.
The heated seat module or memory heated seat
HEATED SEAT SYSTEM 8G - 11
Fig. 2 Heated Seat Element - Typical
1 - Seat Back Wire Harness
2 - Heated Seat Wire Harness Connector
3 - Heated Seat Cushion Element
adjustable pedal module supplies five-volts to one
side of each sensor, and monitors the voltage drop
through the sensor on a dedicated hardwired return
circuit. Each module uses this temperature sensor
input to monitor the temperature of the seat cushion,
and regulates the 12v current flow to the heated seat
elements accordingly.
DIAGNOSIS AND TESTING - HEATED SEAT
ELEMENTS
The wire harness connectors for the heating ele-
ments are located under the seat. For circuit descrip-
tions and diagrams, refer to section 8W, Wiring.
NOTE: When checking heated seat elements for
continuity, be certain to move the heating element
being checked. Moving the element, such as sitting
in the seat will eliminate the possibility of an inter-
mittent open in the element which would only be
evident if the element was in a certain position.
Failure to check the element in various positions
could result in an incomplete test.
FRONT SEAT SYSTEM
(1) Locate the memory heated seat adjustable
pedal module. Disconnect the appropriate connector
from the module. Refer to the wiring section for
details.
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