Grand Caravan V6-4.0L (2008)
Solar Sensor: Description and Operation
Sensor-Infrared
Description
DESCRIPTION
The infrared sensor is used only on models equipped with the automatic temperature control (ATC) heater-A/C system. The infrared sensor is located in
the front overhead console. The infrared transducer consists of an infrared transducer (1) contained within a black molded plastic housing (2) with an
integral wire connector receptacle (3). The integral mounting tab (4) allows the infrared sensor to be secured with one screw to the overhead console.
Operation
OPERATION
The infrared sensor detects thermal radiation emitted by the front seat occupants and surroundings and converts its data into a linear pulse width
modulated (PWM) output signal, which is sent to the compass temperature module (EOM) through a two-wire lead and connector of the vehicle wire
harness. The EOM sends a message over the controller area network (CAN) IHS bus where it is read by the automatic temperature control (ATC)
A/C-heater control. The ATC A/C-heater control uses the infrared sensor data as one of the inputs necessary to automatically control the interior cabin
temperature level. By using thermal radiation (surface temperature) measurement, rather than an air temperature measurement, the ATC heating-A/C
system is able to adjust itself to the comfort level as perceived by the occupants. This allows the ATC system to compensate for other ambient conditions
affecting comfort levels, such as solar heat gain or evaporative heat loss.
The ATC system logic responds to the infrared sensor message by calculating and adjusting the air flow temperature and air flow rate needed to properly
obtain and maintain the selected comfort level temperature of the occupants. The EOM continually monitors the infrared sensor circuits, and will store a
diagnostic trouble code (DTC) for any problem it detects.
The infrared sensor is diagnosed using a scan tool.
The infrared sensor cannot be adjusted or repaired and must be replaced if inoperative or damaged.
