Grand Caravan V6-3.3L VIN R (2005)
Power Seat Control Module: Description and Operation
Vehicles equipped with heated seats utilize two heated seat modules. The heated seat modules are located under the front seats, where they are secured to
the seat cushion pans. Each heated seat module has three connector receptacles that allow the modules to be connected to all of the required inputs and
outputs through the seat wire harness.
The heated seat modules are an electronic microprocessor controlled device designed and programmed to use inputs from the ignition switch, heated seat
switch and the heated seat sensor to operate and control the heated seat elements in the front seat.
The heated seat module operates on fused battery current received from the Integrated Power Module (IPM). The module is grounded at all times
through the seat wire harness. Inputs to the module include a resistor multiplexed heated seat switch request circuit for the heated seat switch and the
heated seat sensor inputs from the seat cushions of each front seat. In response to those inputs the heated seat module controls battery current feeds to the
heated seat elements.
When a heated seat switch request signal is received by the heated seat module and the enable input is high, the heated seat module energizes the selected
heated seat sensor circuit and the sensor provides the module with an input indicating the surface temperature of the selected seat cushion.
The Low heat set point is approximately 36° C (95° F), and the High heat set point is approximately 40° C (104° F). If the seat cushion surface
temperature input is below the temperature set point for the selected temperature setting, the heated seat module energizes an N-channel Field Effect
Transistor (N-FET) within the module which energizes the heated seat elements in the selected seat cushion and back. When the sensor input to the
module indicates the correct temperature set point has been achieved, the module de-energizes the N-FET which de-energizes the heated seat elements.
The heated seat module will continue to cycle the N-FET as needed to maintain the selected temperature set point.
