DESCRIPTION
Vehicles with the optional heated seat system can be visually identified by the two heated seat switches located in the Radio Receiver Module (RRM), in the center of the instrument panel. The heated seat system allows the driver and front seat passenger to select from two different levels of electrical seat heating (HI and LO).
The heated seat system includes the following major components
- Heated Seat Switches - Two heated seat switches are used per vehicle, one for each front heated seat. Both switches are integral to the Radio Receiver Module (RRM). Refer to «SWITCH, HEATED SEAT, DESCRIPTION»(ref-646252-S24800507332014072800000) .
- Comfort Seat and Wheel Module - One Comfort Seat and Wheel Module (CSWM) is used per vehicle. The CSWM is mounted under the driver seat and contains the control logic and software for the front heated seat system. Refer to «MODULE, COMFORT SEAT AND WHEEL, DESCRIPTION»(ref-646224-S37576449982014072800000) .
- Heated Seat Elements - Four heated seat elements are used per vehicle. Two heated seat elements for each seat, one on the seat back cushion and the other on the seat bottom cushion. The heated seat elements are hard-wired to the CSWM. Refer to «PAD, HEATER, DESCRIPTION»(ref-646252-S18370692542014072800000) .
OPERATION
The Comfort Seat and Wheel Module (CSWM) directly provides power to the seat heating elements in the seat cushions and backs for seat heating. Fused ignition switch output (run) circuits are used, so that the heated seat system will only operate when the ignition switch is in the On position and the engine is running. The module responds to heated seat thermistor sensor feedback from each heating element and ignition switch status inputs by controlling the electrical output to the front seat heating elements. The heated seat system will turn off automatically whenever the ignition switch is turned to any position except On.
Pressing a heated seat switch once will select high-level heating and pressing the same switch a second time will select low-level heating. Pressing the switch a third time will shut the heating elements off. When the switch is pressed, the CSWM energizes an integral solid-state relay, which supplies battery current to the heating elements. If high-level heating is initially selected, the heated seat control system will automatically switch to a lower level temperature after 50 minutes of continuous operation at the desired temperature level. Operation in the low-level setting automatically turns to off after 45 minutes.
The driver seat heat system and passenger seat heat system each consist of a cushion element connected in parallel with a back element. Both systems have a seat cushion with a thermistor sensor that provides feedback to the CWSM. Both systems seat cushion and seat back have a thermostat that will request the heated seat to turn off if the temperature reaches or exceeds 135 °F (+/- 9 ° F). The CSWM will also turn off the heated seat elements if an open or short in the heating element circuit is detected.
Auto On Feature
The Auto On feature is a customer configurable feature that when enabled will activate the driver heated seat and heated steering wheel on engine start based on ambient temperature. If Auto On feature is enabled, and the ambient temperature is at or below 40° F the CSWM will activate the driver heated seat and heated steering wheel feature at the high level during engine start. This feature also works with Remote Start.
Battery current is directed to the heated seat elements by the Comfort Seat and Wheel Module (CSWM). The CSWM will energize the heated seat elements when a heated seat switch is pressed on.
As electrical current passes through each heated seat element, the resistance of the wire used in the element disperse some of the electrical current in the form of heat. The heat produced by the heated seat element then radiates through the seat bottom and seat back covers, warming the seat covers and its occupant.
The heated seat elements cannot be repaired and must be replaced if inoperative or damaged.
When either of the hard or soft front heated seat switches are pressed with the engine running, a signal is sent to the Comfort Seat and Wheel Module (CSWM) over the Controller Area Network (CAN) data bus, signaling the module to energize the heating elements for the selected seat. Indicator lamps illuminate for each heated seat switch and indicate the level of heat in use (HI or LO). Pressing a heated seat switch once will select high-level heating and pressing the same switch a second time will select low-level heating. Pressing the switch a third time will shut the heating elements off.
The CSWM energizes the integral solid-state relays that supply battery current to the heating elements. During high-temperature level operation, the HI indicator illuminates on the U-Connect Touch ™ screen. After 50 minutes of high-temperature level heating, the CSWM automatically lowers the heat level to low. At that time, the LO indicator illuminates on the U-Connect Touch ™ screen. Operation on the low-temperature level setting will automatically turn off after 45 minutes.
The individual front heated seat switches located in the U-Connect Touch ™ screen module cannot be adjusted or repaired. If a front heated seat switch or indicator is inoperative or damaged, the entire U-Connect Touch ™ screen module must be replaced. Refer to REMOVAL .
See also:
• DTC INDEX