Pinpoint Test A : Both Heated Rear Seats Are Inoperative: Notes

Refer to Climate Controlled Seats for schematic and connector information.

Normal Operation and Fault Conditions 

If equipped with the snowplow feature and the snowplow mode is inactive, the rear heated seat module receives power through the normally closed contacts of the snowplow relay (integral to the BJB). When the LH or RH heated rear seat control switch is activated with the ignition ON, a momentary ground signal is supplied to the heated seat module to operate the system. The system cycles through high heat mode, low heat mode or OFF, each time the switch is pressed. The heated seat module supplies voltage to the LH or RH rear seat cushion and backrest heater mats, which are connected in series. Seat temperature is maintained by the heated seat module using a sensor contained within each cushion heater mat. The heated seat module supplies a reference voltage to the temperature sensor and monitors the return signal from the temperature sensor for controlling current flow to the heater mats. The heated seat module remains ON, heating the seat and maintaining temperature until switched OFF or the ignition voltage is switched OFF.

Possible Sources 

• Fuse(s)
• Wiring, terminals or connectors
• Heated seat module
• BJB

Visual Inspection and Diagnostic Pre-checks 

• If equipped with the snowplow feature, verify that snowplow mode is not active. For information about snowplow mode, refer to the Owner's Literature.
• Verify BCM fuse 36 (15A) and BJB fuse 94 (15A) (without snowplow feature) or 104 (15A) (with snowplow feature) are OK.