Description And Operation: Notes
DESCRIPTION
The heated seat system consists of the following components:
| 1. | Refer to BODY CONTROL MODULE (BCM) . |
| 2. | Refer to UCONNECT® TOUCH SCREEN (if equipped). |
| 3. | Refer to INTEGRATED CENTER STACK (ICS) MODULE . |
| 1. | Refer to COMFORT SEAT AND WHEEL MODULE (CSWM) . |
| 2. | Refer to HEATED SEAT ELEMENTS (Seat Back and Seat Bottom). |
| 3. | Refer to HEATED AND VENTILATED SEAT BLOWER MOTORS . |
| - | Refer to VENTILATED SEAT PLENUMS . |
OPERATION
When the occupants of the front seats request the activation of the heated seats (two heating levels) or the steering wheel through the control panel, the command is sent via Local Interface Network (LIN) bus to the BCM. The BCM translates the command received and sends it via Controller Area Network - Interior High Speed (CAN-IHS) to the CSWM. The CSWM supplies the heater pads placed on the front seat back rests and cushions and will receive the signal directly from the two temperature sensors (one per seat) in the cushions, to learn the temperature of the seats and use the correct strategies for supplying the heater pads.
The CSWM monitors the operation of the system and will generate the appropriate Diagnostic Trouble Codes (DTC) in the event of failure.
When operating the heated seat switch, one of three switch positions can be selected: OFF, LOW, or HIGH. The CSWM can provide three levels of power to the heating elements for the HIGH setting. These power levels are changed by modulating the pulse width of the positive side of the circuit. The strategy used by the CSWM is to operate the heating element at the highest pulse-width until the target time or temperature for the pulse width is met. The CSWM then reduces the pulse width and repeats this process until the system times out. When the LOW setting is selected, the pulse width remains at 25% until the target temperature or time is reached (205 minutes for leather and 115 minutes for fabric). The following table provides an overview of the adjustment strategy used to control the amount of current provided to the seat heating elements:
| Parameter name | Definition | Unit | Leather | Fabric |
|---|---|---|---|---|
| Temp_OFF | Maximum temperature for heating program | °C / °F | 67 / 153 | 55 / 131 |
| DH_S3 | PWM for heating - high level 3 | s | 100% | 100% |
| TempSH3 | Maximum temperature for seat heating level 3 | °C / °F | 50 / 122 | 34 / 93 |
| T1S | First timing program for seat heating | min. | 25 | 20 |
| DH_S2 | PWM for heating level 2 | s | 40% | 70% |
| TempSH2 | Maximum temperature for seat heating level 2 | °C / °F | 55 / 131 | 38 / 100 |
| T2S | Second timing program for seat heating | min. | 85 | 35 |
| DH_S1 | PWM for heating level 1 | s | 40% | 34% |
| TempSH1 | Maximum temperature for seat heating level 1 | °C / °F | 60 / 140 | 43 / 109 |
| T3S | Third timing program for seat heating | min. | 145 | 95 |
| DL_S1 | PWM for heating level Low | s | 25% | 25% |
| TempSL1 | Maximum temperature for heating program Low | °C / °F | 65 / 149 | 48 / 118 |
| T4S | Fourth timing program for seat heating | min. | 205 | 115 |
Power supply of the seat heating control unit reaches from relay switch located in the luggage compartment fuse box, through a line protected by a fuse.
Relay switch receives an ignition-operated power supply (INT) from the line protected by a fuse.
The control unit then connects via CAN to the other network nodes.
The BCM receives a direct power supply from the battery through the line protected by a maxi fuse located in the engine compartment junction unit.
The BCM receives an ignition-operated power supply (INT). This signal is used, amongst other things, to "wake up the network".
The coil activation signal reaches the BCM via the LIN line.