SEAT WARMER SYSTEM

id091300101200


Purpose

•  The seat warmer system warms the front seat cushion and front seat back using the seat warmer unit.

Function

•  The seat warmer unit warms the seat cushion and seat back by supplying power to the built-in filaments.
•  The seat warmer unit can adjust the temperature between 3 levels.
•  The temperature level of the seat warmer unit changes each time the seat warmer switch is pressed.
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•  The seat warmer control unit supplies power to the seat warmer unit and increases the temperature around the seat back and seat cushion up to the average temperature which is applied to the temperature level.

Switch display

Temperature level

Average temperature around seat warmer unit

With manual air conditioner system

With full-auto air conditioner system

Seat cushion side

Seat back side
0
—
1
Approx. 37°C {99°F}
2
Approx. 40°C {104°F}
Approx. 42°C {108°F}
3
Approx. 42°C {108°F}
Approx. 47°C {117°F}

•  The seat warmer control unit detects the average temperature around the seat warmer unit (seat cushion side) based on a signal from thermostat (seat cushion side) to prevent overheating, cuts off the power supply to the seat warmer unit when the temperature reaches the specification, and decreases the average temperature below the specified temperature.
•  When the seat warmer control unit detects that the average temperature around the seat warmer unit (seat cushion side) decreases below the specified temperature based on a signal from the thermostat, power is supplied to the seat warmer unit again to increase the temperature up to the specified temperature.

Temperature level
Average temperature around seat warmer unit (seat cushion side)
Cloth type
Leather type
Increase start temperature
Decrease start temperature
Increase start temperature
Decrease start temperature
0
—
1
Approx. 22°C {72°F}
Approx. 24°C {75°F}
Approx. 22°C {72°F}
Approx. 24°C {75°F}
2
Approx. 32°C {90°F}
Approx. 34°C {93°F}
Approx. 32°C {90°F}
Approx. 34°C {93°F}
3
Approx. 38°C {100°F}
Approx. 40°C {104°F}
Approx. 39°C {102°F}
Approx. 41°C {106°F}

•  The seat warmer control unit maintains a constant average temperature around the seat warmer unit by continuing to supply power to the seat warmer unit.

Ex.) Cloth-type temperature level is 3:

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Structural view

•  The seat warmer switch is built into the climate control unit. (full-auto air conditioner)
•  The seat warmer switch is built into the indicator unit. (manual air conditioner)
•  The seat warmer unit is adhered to the front seat cushion and front seat back.
•  The seat warmer control unit is located on the bottom of the passenger-side front seat.
•  
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System wiring diagram

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Operation


Ex.) Seat warmer temperature level on cloth-type driver's side is set at 3 (with full-auto air conditioner system):

1.  When the climate control unit detects the seat warmer switch (driver’s side) operation, it sends (1) a switch operation signal (temperature level “3”) to the CPU of the seat warmer control unit.

2.  When the CPU of the seat warmer control unit receives the switch operation signal (temperature level “3”) from the climate control unit, it sends current to the transistor to turn it on (2).

3.  Current flows (3) to the FET by turning the transistor on.

4.  The current flows (4) to the relay coil to turn the relay switch on (5).

5.  When the relay switch is turned on, the ground circuit is established and the current flows (6) to the seat warmer unit in the driver’s side seat cushion and seat back.

6.  The heating wire warms up (7) by the current sent to the seat warmer unit in the driver’s side seat cushion and seat back.

•  When the climate control unit detects that the temperature around the seat reaches approx. 40°C {104°F}, the power supply is cut off.
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Ex.) Seat warmer temperature level on cloth-type passenger-side is set at 3 (with manual air conditioner system):

1.  When the indicator unit detects the seat warmer switch (passenger’s side) operation, it sends (1) a switch operation signal (temperature level “3”) to the CPU of the seat warmer control unit.

2.  When the CPU of the seat warmer control unit receives the switch operation signal (temperature level “3”) from the indicator unit, it sends current to the transistor to turn it on (2).

3.  Current flows (3) to the FET by turning the transistor on.

4.  The current flows (4) to the relay coil to turn the relay switch on (5).

5.  When the relay switch is turned on, the ground circuit is established and the current flows (6) to the seat warmer unit in the passenger’s side seat cushion and seat back.

6.  The heating wire warms up (7) by the current sent to the seat warmer unit in the passenger’s side seat cushion and seat back.

•  When the indicator unit detects that the temperature around the seat reaches approx. 40°C {104°F}, the power supply is cut off.
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Fail-safe

•  Function not equipped.