Battery positive voltage (B+) is supplied to both front heated seat modules from the rear fuse block IGN  3 fuse. Therefore, the heated seats will operate only with the ignition switch in the ON position. Battery positive voltage is also supplied at all times to each front seat module from the rear fuse block HTDST LF Fuse for the left seat module, or HTDST RF Fuse for the right heated seat module.

Each front heated seat is controlled by a separate heated seat switch. When the front heated seat switch is pressed, a ground path is momentarily applied to the heated seat switch input of the front heated seat module. The heated seat module then applies battery positive voltage (B+) to the front heated seat heating elements. The front heated seat module monitors the seat surface cushion temperature through a thermistor and maintains a pre-determined temperature.

When the heated seat is off and the front heated seat switch is pressed once, the front heated seat module will set the heated seat temperature to HIGH. The front heated seat module supplies battery positive voltage (B+) to the front heated seat switch high heat LED. When pressed again, the heated seat temperature is then set to LOW, and the front heated seat module supplies battery positive voltage (B+) to the front heated seat switch low heat LED. After the third press of the front heated seat switch, the front heated seat module removes battery positive voltage (B+) to the front heated seat heating elements. The front heated seat module will also turn off the heated seat whenever the ignition switch has been turned to the OFF position.

Battery positive voltage (B+) is supplied to both rear heated seat modules from the rear fuse block IGN 3 Fuse. Therefore, the heated seats will operate only with the ignition in the ON position. Battery positive voltage (B+) is also applied at all times to the rear heated seat modules from the rear fuse block; HTDST LR Fuse for the left heated seat module, or, HTDST RR Fuse for the right heated seat module.

Each rear heated seat is controlled by a separate heated seat switch. Both rear heated seat switches are grounded via a ground circuit provided by the associated rear door module. When the heated seat switch is pressed, the rear door module heated seat switch input is momentarily grounded via the rear heated seat switch contact. In response to this input, the rear door module sends a simple bus interface (SBI) message to the left front door module (LFDM) indicating that the appropriate rear heated seat needs to be activated. In response to this message, the LFDM sends a class 2 message to the rear integration module (RIM) indicating that the rear heated seat needs to be activated. The rear heated switch input of the appropriate heated seat module is then grounded via the rear heated seat control of the rear integration module (RIM). The rear heated seat module then applies or removes battery positive voltage (B+) to the rear heated seat heating elements. The rear heated seat module monitors the seat surface temperature through a thermistor and maintains a pre-determined temperature.

When the heated seat is off and the rear heated seat switch is pressed once, the rear heated seat module will set the heated seat temperature to HIGH. The rear door module then supplies battery positive voltage (B+) to the rear heated seat switch high heat LED. When pressed again, the heated seat temperature is set to LOW. The rear door module then supplies battery positive voltage (B+) to the rear heated seat switch low heat LED. After the third press of the rear heated seat switch, the rear heated seat module removes battery positive voltage (B+) to the rear heated seat heating elements. The rear heated seat module will also turn off the heated seat whenever the ignition switch has been turned the OFF position.

The ON/OFF status of the front heated seats is reported to the rear integration module (RIM) via the status output circuit of each front heated seat module. The RIM inhibits heated seat function for all heated seats via the inhibit input circuit according to the level of load management. During Load Shed 0, the RIM leaves the inhibit circuit open so that each heated seat module is in the high heat mode of operation. During Load Shed 1, the RIM will cycle the signal from high to low every 0.25 seconds to control the heat level to the low setting. During Load Shed 2, the RIM will supply a constant ground via the inhibit input circuit to the heated seat modules. All heated seats are turned off during Load Shed 2 and the front heated seat module or rear door module will deactivate the appropriate LED.