geez i hate the sales staff for starting rumors like that, the "cooled" seats are just fans that suck the air from/though the cushions via a special open mat under the upholstery and blow it into the back seat (good fart transport system to the kids) the cooling effect is the sweat evaporation. what year ya got? 16 and older or 17 and up with the new motor? ase and gm master tech and specialize in driveablity, diesels and those ungodly communication/electrical issues nobody else can fix at our buick/gmc dealer
the most common failure in the drivers seat is the little buzzer motor on the outboard side, the flexing of the cushion breaks the wires off the motor, once outside of the free replacement during bumper to bumper warranty its easy enough to take apart and reconnect the wires
the 11-16 bosch injection pump failures are covered under powertrain/diesel coverage as long as the truck hasn't been programmed or fuel contamination proven, warranty time is 21 hours and cash is 30, so i wanna find a reason to void the warranty
lowest mileage ive done was 4700 miles, still on the factory oil fill, the injection pump is 2 pumping valves driven by a 3 lobed cam running off the camshaft timing gear, solid bucket lifters with a single double tapered no axle roller rides on the pump cam, the problem is the buckets aren't prevented by anything other then the football shaped roller wanting to stay straight, it starts with one of the rollers skipping and putting a scar on the lobe which gets worse and the resultant metal erodes fuel pressure regulator #2 (front of left fuel rail, fpr 1 is in top of pump) to the point it bypasses everything back to the tank, it needs minimum 1200 psi to start and idle like crap, 5000ish to idle normally, peaks at 26k on 11-13 and 29k on 14-16.
ive heard the 17- L5P with the nippondenso pump and solenoid style injectors (older runs piezo) has a similar mode of self destruction but haven't seen one do it yet