Why are my seat heaters not working?

Seat heaters on GM cars are controlled by the body control module using a sophisticated Controller Area Network (CAN). If portion of the CAN network goes down, some or all of the components controlled by the network may not work. Usually this event will set a Diagnostic Trouble Code (DTC) which may or may not turn on the Check Engine Light (CEL). If the CEL is on, or even if it is not, we can scan the CAN network looking for DTC's. Once we know where the problem lies, we can diagnose the problem and clear the code to restore functionality.