Twelve recalls in the first year of a brand-new body — buyable, but only with the whole recall history in hand.

The ten-speed's control valve wears and loses hydraulic pressure, producing harsh shifting, a service-engine-soon message, reduced performance and diagnostic code P0747. At worst it locks the rear wheels: one owner reports exactly that at freeway speeds, and another had the transmission fail into neutral with the override so stuck that dealership technicians could not release it. On the 2021 diesel this is safety recall 24V797, a free software update. On every 2021, GM's Special Coverage for the control valve runs fifteen years or 150,000 miles and pays for a new valve body. Feel for shudder and harsh shifts on the test-drive and ask whether the valve body has been done.

Two separate launch-year campaigns cover ways this truck can stop helping you. Recall 21V739 covers a fuel-pump power control module that can make the pump fail or run intermittently, interrupting fuel flow and stalling the engine unexpectedly; dealers replace the module free. Recall 21V455 covers a software fault that can cause a loss of power steering assist at startup or while driving, fixed by a dealer or over the air. One owner outside the campaigns still paid out of pocket when both the fuel pump and its control module failed together, leaving the truck needing a tow. Verify both by VIN.

The launch year produced an unusual cluster of belt campaigns and they cover different failures, so all four need checking. 20V792 covers front-row-centre belt brackets not secured to the seat frame. 20V811 covers incorrect bolts used at one or more belt fastening locations. 21V190 covers third-row outboard belts entrapped or misrouted behind the seat-folding mechanism, which damages the webbing. 22V617 covers a third-row buckle retaining rivet that was improperly formed. Separately, recall 20V735 covers front seats whose attachment bolts may not have been reinstalled after an assembly-line repair. All are free inspections and replacements.

DFM — Dynamic Fuel Management, the successor to AFM that can shut down any combination of the eight cylinders — uses the same collapsible-lifter idea and fails the same way, but mechanics report it failing more often and earlier than the older system. One owner in this year's file had to replace the entire engine for the lifter problem and was left stranded with children in the truck. There is no recall covering the 5.3L for this. Cold-start it and listen for a tick or tap, and treat any misfire code as a reason to walk.

The new independent rear suspension rides far better — a first-week owner called it smooth where the old truck was truck-like — but it brings its own wear. Owners report rear-axle grinding that dealers recognise as a documented issue with no recall behind it: fluid changed, figure-eights driven, grinding still there. On air-suspension trucks the picture is worse. Two hands-on teardowns show the compressor seizing solid with its piston scored by grit and moisture, and one mechanic's verdict is that the units are effectively disposable regardless of brand because of where they live under the truck. Coil-sprung trims avoid the problem entirely.

The new diesel gets its own coverage and its own problems. GM's Special Coverage for a cylinder-2 glow-plug failure runs fifteen years or 150,000 miles from first service. Recall 24V797 covers the diesel transmission control valve. Uncovered, one owner reports a recurring engine wiring-harness fault serious enough to file a safety complaint about. Mechanics also flag diesel-particulate-filter and fuel-quality sensitivity on this engine. If you are buying the diesel, confirm both the glow-plug coverage and 24V797 by VIN.