Common GMC Sierra 2500HD Replacement Parts, 2015-2019

The Sierra 2500HD K2XX ran from 2015-2019 and is L5P Duramax from 2017. After enough of these come across the parts counter you start to see the same short list of components over and over. Here is what owners of this generation actually end up buying, and what to know before you order.

Drivetrain and Transfer Case

The usual tell is a four wheel drive light that flashes and never engages. Owners who do mostly short trips see this sooner than the mileage suggests.

Common parts in this group: transfer case encoder motors, front differential actuators, u-joints, CV axles, driveshaft center bearings.

Worth knowing: Transfer case shift motors and encoders are matched to the specific case, and the module reads their position directly.

Glass and Wipers

The usual tell is wipers that park in the wrong position. Owners who do mostly short trips see this sooner than the mileage suggests.

Common parts in this group: wiper blades, wiper transmissions, wiper motors, washer pumps, rain sensors.

Worth knowing: GM wiper arms and blades are matched to the specific windshield curvature, and length is not the only variable.

Cooling System

The usual tell is having to top off the surge tank more than once a year. Owners who do mostly short trips see this sooner than the mileage suggests.

Common parts in this group: radiators, water pumps, thermostats, coolant hoses, cooling fans.

Worth knowing: Aftermarket radiators frequently use fewer rows or thinner tanks than the original, which shows up as a heat problem only when you tow.

Interior

The usual tell is a console lid hinge that has cracked at the pivot. Catch it early and it is a parts bill. Ignore it and it becomes a parts and labor bill.

Common parts in this group: floor liners, carpet floor mats, console lids, seat covers, shift knobs.

Worth knowing: GM Accessories liners are laser-measured to the specific floor pan and retain the factory anchor posts, which is a safety item.

Electrical and Charging

The usual tell is warning lights that appear in clusters and then clear themselves. Worth checking at the same time you rotate tires, since the wheel is already off.

Common parts in this group: batteries, battery cables, alternators, starters, body control modules.

Worth knowing: Auxiliary and stop-start systems use AGM batteries, and dropping a flooded battery in is a short path to a repeat failure.

Exhaust and Emissions

The usual tell is an exhaust tick on cold start that quiets as the manifold expands. Heat is the accelerant on this one, which is why it shows up faster here than up north.

Common parts in this group: catalytic converters, oxygen sensors, DEF injectors, diesel particulate filters, EVAP purge valves.

Worth knowing: Diesel aftertreatment parts are tightly integrated with the calibration.

Before You Order

Have the VIN ready. On a Sierra 2500HD the same model year can carry two or three different engines and several suspension packages.
Check the SPID label in the glove box or console for your RPO codes.
Front and rear parts are rarely the same number, even when they look identical.
If the part is electrical, confirm the fit before you order. Electrical parts are not returnable at any GM dealer, including us.

We are a factory GM dealer, not a reseller, so what you order is the same part the service drive installs. Browse our GMC OEM parts catalog or search for Sierra 2500HD parts.