Pacifica V6-3.8L VIN L (2005)
Seat Heater Control Module: Description and Operation
Heated Seat Module - 2nd Row Seats
Heated Seat Module - 2nd Row Seat
The 2nd row seat heated seat module is located in the rear seat center console, where it is secured by two retaining fasteners. The heated seat module has
a single electrical connector receptacle that connects all of the inputs and outputs through the seat and body wire harnesses.
The heated seat module is an electronic microprocessor controlled device designed and programmed to use inputs from the battery, the two heated seat
switches and the two heated seat sensors to operate and control the 2nd row seat heated seat system. The module is also designed to provide outputs to
the heated seat elements in both 2nd row seats and the two heated seat indicator lamp Light-Emitting Diodes (LEDs) in each 2nd row heated seat switch.
The heated seat module is able to perform some self-diagnosis of certain heated seat system faults and provide feedback of that diagnosis through the
heated seat switch indicator lamps.
The heated seat module cannot be repaired. If the heated seat module is damaged or faulty, the entire module must be replaced.
When a 2nd row heated seat switch is depressed a resistance (ohms) signal is sent to the heated seat module, the module energizes the proper indicator
LED (Low or High) in the switch by grounding the indicator lamp circuit to indicate that the heated seat system is operating. At the same time, 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
seat cushion.
The Low heat set point is about 35° C (95° F), and the High heat set point is about 40° C (104° F). If the heated seat sensor 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. The 2nd row heated seat module operates on fused battery current
received from the integrated power module.
If the heated seat module detects a heated seat sensor value input that is out of range or a shorted or open heated seat element circuit, it will notify the
vehicle operator or the repair technician of this condition by flashing the High and/or Low indicator lamps in the affected heated seat switch. Refer to
Diagnosis and Testing Heated Seat System in the Heated Seat System for flashing LED diagnosis and testing procedures. Refer to Diagnosis and Testing
Heated Seat Module in the Electronic Control Module for heated seat module diagnosis and testing procedures.