Took my new diesel in to Reno GMC for its first service, had an oil change and general inspection, and an update on the software changing the notification of timing belt service mileage. Got it back, and drove off. Tried to turn the heated seat on, and all that happened was a yellow light flashed once, and then nothing. Tried again, same thing. Tried the passenger side, same thing. Tried button mashing and the yellow light would come on again after three button pushes. Called the service writer I dealt with and left a message. He got back to me after about an half hour, and I explained what was going on. He said he wanted to talk to his techs, called back five hours later, saying he hadn't any idea what had occurred. Said he would get with his "brain trust" next week. I have found absolutely NOTHING on the internet relating to this issue.