GM-GMC: GMC Envoy 2003 bottom seats not heating up but back is, seat upholstery, heater elements

Question
"Just the other day I noticed the bottom of the driver side not heating up. I checked the passenger side and it also wasn't working. The back of the seats are working on both sides without any problems. Strangely, today the passenger bottom seat came on briefly but once shut off it never came back on again. Just like I mentioned before the back of the seats are heating up on both sides but the bottom aren't. Can you please help me what might be the cause of this problem?  Thank You Ania"

Answer
I would suspect that the heater elements on the seat bottoms is damaged or has an open circuit.  Not uncommon at all.  Replacement is the only repair.  You can inspect yourself by pulling the seat upholstery up and inspecting the heater grid it will have a burn that is very visible.
Hope this helps