FYI... the driver side seat heater quit. i checked a few things out it turns out the backrest (lumbar) heater had an open circut ( open line ) i removed the seat cover starting at the bottom and found a broken wire right at the bottom, repaired the wire and now it works great! so just for your reference, check continuity on the bottom and back of the seat before you buy a new seat. i called chevy they wanted $250!!!

for a new bottom seat cover (the only way to buy the heating unit is to buy the cover and the heating unit as one)