Know Your Truck

2015–2019 Chevy Silverado HD / GMC Sierra HD common problems and fixes

2015–2016 diesels carry the fuel pump risk; the 2017+ L5P has far fewer fuel pump complaints; trailer brake warnings are common.

What owners should know

Covers 2015–2019 · 6.6L Duramax diesel (LML 2015–2016, L5P 2017–2019) and 6.0L V8 gas · Updated 2026-10-07

The Chevy Silverado HD and GMC Sierra HD are mechanically the same trucks, so these notes cover both, in 2500HD and 3500HD. The diesel changed partway through: the Duramax LML in 2015–2016, and the redesigned Duramax L5P in 2017–2019. Gas trucks use the 6.0L V8.

We counted 953 owner complaints filed with NHTSA for 2015–2019 Silverado HDs and Sierra HDs (retrieved October 5, 2026; each complaint counted once): 386 from LML diesels, 285 from L5P diesels and 236 from 6.0L gas trucks, identified by VIN; the rest (46) couldn't be matched to an HD engine. We left out 23 whose VIN belongs to another vehicle (mostly half-ton Silverados and Sierras). We left out complaints that NHTSA labels only "Silverado" or "Sierra", because the same complaints also appear under the half-ton trucks. Complaint counts show what owners report most often, not how many trucks have a problem.

At a glance

  • 2015–2016 diesels (LML) carry the high-pressure fuel pump (CP4.2) risk.
  • 2017–2019 diesels (L5P) use a different fuel pump and have far fewer fuel pump complaints. Block heater cord recalls address a fire risk.
  • Brake pedal recall on certain 2015–2016 trucks: the pedal can come loose.
  • Trailer brake warnings are frequently reported (93 complaints mention the trailer brake).
  • Gas trucks: the transmission is the most common complaint (about 1 in 7).

2015–2016 Duramax LML: fuel pump

56 of 386 LML complaints mention the fuel pump, CP4, low fuel pressure or code P0087, about 3 times the rate of the 2017–2019 L5P (14 of 285). The LML uses the Bosch CP4.2 pump. When it fails, metal can contaminate the whole fuel system, and repair sources report bills of $8,000 to $15,000. There was no recall.

When buying a 2015–2016 diesel: ask whether the pump was replaced or upgraded, and for fuel filter records.

2017–2019 Duramax L5P

Commonly reported repairs include DEF tank sensors, the MAP sensor, plastic intercooler pipes, and fuel injector electrical connectors that wear from vibration (GM bulletin 23-NA-027 has technicians check the connector before replacing an injector for misfire codes; owners most often mention cylinder 4). 32 L5P complaints mention a fire or flames. GM recalled certain 2017–2019 diesels because the engine block heater cord can short and overheat (recalls 19V328000 and 21V496000). Confirm both are done.

Brakes and trailer brakes

  • GM recalled certain 2015–2016 trucks because the brake pedal pivot nut can loosen, making the pedal loose or inoperative (recalls 16V069000 and 18V578000).
  • Owners frequently report "Service trailer brake system" warnings that can cut the trailer brakes while towing. If you tow, test the trailer brake controller with a trailer connected.

Gas trucks

Transmission complaints are the top topic on 6.0L gas trucks (35 of 236 mention the transmission). Test-drive for harsh or slipping shifts.

Other recalls

  • Dual fuel tanks: a front-tank fuel level sensor on certain 2016–2018 gas 3500s (recall 19V088000), and a rear tank that can collapse and stall the engine on certain 2017–2019 diesels (recall 23V047000)
  • Front seat belt retractors on certain 2017–2018 trucks (recall 17V567000)
  • Several side curtain airbag inflator recalls on certain trucks (20V736000, 21V504000, 24V756000, 26V611000). For 26V611000 (certain 2016 trucks, both roof rail airbags replaced), the repair isn't available yet: NHTSA says GM expects to mail owner letters on November 9, 2026

Before you buy

Researched from owner forums and NHTSA complaints and written by Know Your Truck. These are patterns in what owners report, not a guarantee about any particular truck.

Sources (17)

Common failures & how to fix them

Parts and video buttons search for your 2015-2019 Chevrolet Silverado 2500HD. Always confirm a part fits using your VIN. Brakes, steering, fuel and airbag work affects your safety, so if you're not sure, have a qualified mechanic do it.

  • 2015–2016 Duramax fuel pump (CP4) failure

    Best left to a shop

    Signs: Sudden stalling or no-start, low fuel pressure codes such as P0087.

    Fix: Prevention: change the fuel filter on schedule and buy fuel from busy stations. Some owners replace the CP4 with a different pump design as prevention. If the truck stalls or won't start, have a diesel shop confirm the cause (fuel pressure tests, checking the filter for metal) before quoting a pump. A confirmed failure that sent metal through the system usually means a full fuel system replacement.

    Shop: Duramax fuel filterShop: Duramax CP3 conversion kit▶ How-to videos

  • Loose brake pedal (2015–2016)

    Dealer job

    Signs: The brake pedal feels loose or doesn't work right.

    Fix: Covered by GM recalls 16V069000 and 18V578000 on certain 2015–2016 trucks: the dealer adds adhesive to the brake pedal pivot nut and reinstalls it at a higher torque. Recalls cover only specific trucks, so check this VIN at nhtsa.gov/recalls to see if it's included and whether the repair was done.

    May be covered free by recall 16V069000 / 18V578000. Check the VIN at nhtsa.gov/recalls.

  • Block heater cord fire risk (2017–2019 diesels)

    Dealer job

    Signs: A burnt or melted block heater cord or plug.

    Fix: Covered by GM recalls 19V328000 and 21V496000 on certain 2017–2019 diesels with the block heater: the dealer replaces the block heater and cord. Don't use the block heater until it's checked. Recalls cover only specific trucks, so check this VIN at nhtsa.gov/recalls to see if it's included and whether the repair was done.

    May be covered free by recall 19V328000 / 21V496000. Check the VIN at nhtsa.gov/recalls.

  • 'Service trailer brake system' warning

    Easy DIY

    Signs: Trailer brake warnings that cut the trailer brakes while towing.

    Fix: Start with the simple things: clean and inspect the 7-pin trailer connector and the trailer's wiring. If it continues, have a dealer read the codes and diagnose the trailer brake module and wiring before replacing parts.

    Shop: 7 pin trailer connector▶ How-to videos

  • L5P cracked intercooler pipe

    Easy DIY

    Signs: A loud pop, then low power and limp mode.

    Fix: Confirm the boost leak first (look for a cracked pipe or a loose coupler). A cracked plastic charge pipe is replaced; many owners upgrade to a metal pipe.

    Shop: L5P Duramax intercooler pipe▶ How-to videos

Each year in this generation

Owner complaints filed with NHTSA, compared with the typical truck of the same kind and model year. Open a year for its recalls and complaints.

Chevrolet Silverado 2500HD

Chevrolet Silverado 3500HD

GMC Sierra 2500HD

GMC Sierra 3500HD

Factory maintenance schedules

Going to look at one?Bring our free inspection checklist, with these known problems added →