GMC.com provides an owner's manual for the GMC Sierra 2500 HD as of 2015. The manual provides comprehensive information about the Sierra 2500 HD, including about instruments and controls, driving and operating, and vehicle care. The General Motors website also offers a "Getting to Know Your Vehicle" manual.
From the GMC website homepage, move the mouse over the For Owners tab on the top menu and choose Manuals from the drop-down menu. The page automatically loads the manuals for cars released in 2015. Click the View 2015 Owner's Manual under Sierra 2500HD to view the manual online or download it on a device. The manual is available in .pdf format.