Controlling The Seat Climate

Fig 1: Identifying Seat Climate

Courtesy of VOLVO CARS CORPORATION

The seat heaters for the front seats are activated using the switches on the climate control module (CCM) (4/6). The rear seats are activated using the rear seat heaters switch. The function is normally switched off. There are three different temperature settings. When the seat heaters are activated, the highest temperature is preset. On or two further presses of the button then reduce the temperature by one or two settings respectively. The status of the indication is displayed via LEDs. The climate control module (CCM) transmits information about the selected temperature to the relevant seat heating module (SHM) on the relevant LIN bus. The seat heating module (SHM) then controls the current to the heater pads. Each control module then transmits its present status to the climate control module (CCM).

Communication between the climate control module (CCM) and each seat module takes place in the following way:

LIN bus 1: 

• the Seat heating module (SHM) left, front (ECC and ETC) or ventilation left (9/12) (only ECC)
• at heating module (SHM), left rear (9/14) (option)

LIN bus 2: 

• the Seat heating module (SHM) right, front (ECC and ETC) or ventilation right (9/13) (only ECC)
• seat heating module (SHM), right rear (9/15) (option)

The climate control module (CCM) receives information from the central electronic module (CEM) (4/56) about the type of seat and upholstery via the controller area network (CAN). The levels for high and low temperature are adapted for the relevant seat and upholstery by the climate control module (CCM). To a certain extent, the levels for high and low temperature can be adapted to the wishes of the customer using the diagnostic tool.

Depending on vehicle model and options selected by customers, seat ventilation may be found. This as well can be customized using the diagnostics tool. The same applies to the time during which seat heating shall be activated after being turned on.