I had to have both passenger and drivers side seat bottom seat heaters replaced in my 14 Sierra. Both had an open fault circuit according to dealer. Wouldn't cover it for it was a year out of warranty and just had a tick over 40k miles..Happened in 2018. These things are junk. Even after the new cushion heaters were installed, I barely feel any heat coming out of them on high. Poor design. poor product testing. For trucks costing almost 50k or more, I expected a better built product. Oh yeah, while having the heaters replaced, also had to have a drivers side door lock actuator replaced at the same time. That's another failure story. Now I have a drivers side vent actuator fail, blows hot air out drivers side vents when the A/C is on. Charged me 90 buck to test it and tell me what was wrong. Wants $900.00 to fix it. Says dash needs to come completely apart to replace it. Shall I go on? Uhhhhg.