Heated Seat Module - Operation

OPERATION

The Heated Seat Module (HSM) controls the heated seat system. The HSM responds to heated seat switch messages and ignition status inputs by controlling the 12 volt Direct Current (DC) output to the seat heating elements through integral solid-state relays.

When either of the front heated seat switches in the U-Connect Touch(TM) screen module are pressed, the module sends a message over the Controller Area Network (CAN) data bus to the HSM, signaling the HSM to energize the heating elements for the selected seat.

The HSM energizes the integral solid-state relays that supply battery current to the heating elements. When high-temperature level heating is initially selected, the HSM provides a boosted high-heat level during the first four minutes of operation. After the first four minutes have passed, the HSM then drops the heat output to the normal high-temperature level for the next 26 minutes of operation. After 30 minutes of high-temperature level heating, the HSM automatically lowers the heat level to low. At that time, the number of illuminated indicator lamps for the respective heated seat change from two to one, indicating the temperature level change. Operation on the low-temperature level setting will automatically turn off after 30 minutes.

The heated seat system operates on battery current received through a fused ignition Run circuit, so that the system will only operate when the ignition is in the Run position. The heated seat system will turn off automatically whenever the ignition is set to any position other than Run.

The HSM is diagnosed using a scan tool and will automatically turn off the heating elements if it detects an open or low short in a heating element circuit Testing and Inspection.