Concorde V6-2.7L VIN V (2001)
Seat Heater: Description and Operation
HEATED SEATS
The controls for the heated seats are located on the side of each seat. The system offers two seat temperature settings of approximately 98.6 F
(LO) and approximately 107.6 F (HI).
As the temperature in the seat rises, the Negative Temperature Coefficient (NTC) resistance decreases and the voltage reading detected by the
MHSMM increases. The seat heater output is deactivated once the voltage reading reaches it's upper threshold for either setting, high or low.
As the temperature decreases, the voltage reading decreases until the lower threshold is reached for either setting high or low. At this point the seat
heat output is activated once again and this cycle repeats itself as long as the seat heat request is ON. The thresholds for low and high settings are
preprogrammed into the MHSMM memory.
The heated seat switch contain resistors pulled up to ignition which are processed by the MHSMM as voltage readings indicating desired heat
setting high or low.
HEATED SEAT ELEMENT
The heated seat system includes four seat heating elements two in each front seat, one for the seat cushion and the other for the seat back. All
models use two resistor wire heating elements for each seat that are connected in series with the Heated Seat Module (HSM). The temperature
sensor is a Negative Temperature Coefficient (NTC) thermistor. One temperature sensor is used for each seat, and it is located on the seat cushion
heating element for all models.
The seat heating elements are sewn into the seat cushion cover trim and seat back cover trim units. The heated seat elements and the temperature
sensor cannot be adjusted or repaired and, if faulty or damaged, the seat cushion cover trim unit or seat back cover trim unit must be replaced.
Refer to Bucket Seat Cushion Cover or Bucket Seat Back Cover in the Removal and Installation of Body for the seat cushion cover trim and seat
back cover trim service procedures.
The heated seat elements resist the flow of electrical current. When battery current is passed through the elements, the energy lost by the resistance
of the elements to the current flow is released in the form of heat. The temperature sensor is a NTC thermistor. When the temperature of the seat
cushion cover rises, the resistance of the sensor decreases. The HSM or MHSM supplies a five-volt current to one side of each sensor, and
monitors the voltage drop through the sensor on a return circuit. The MSM or MHSM uses this temperature sensor input to monitor the
temperature of the seat, and regulates the current flow to the seat heating elements accordingly.
