2011–2014 Chevy Silverado HD / GMC Sierra HD common problems and fixes

The Chevy Silverado HD and GMC Sierra HD are mechanically the same trucks, so these notes cover both, in 2500HD and 3500HD. Engines are the 6.6L Duramax LML diesel, the first Duramax with diesel exhaust fluid (DEF), and the 6.0L V8 gas.

We counted 543 owner complaints filed with NHTSA for 2011–2014 Silverado HDs and Sierra HDs (retrieved October 5, 2026; each complaint counted once): 387 from diesel trucks and 123 from 6.0L gas trucks, identified by VIN; the rest (33) couldn't be matched to an HD engine. We left out 13 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

• The high-pressure fuel pump (CP4.2) is the most expensive known LML failure.
• DEF heaters and NOx sensors are commonly reported emissions repairs.
• Airbag recalls are a top complaint topic. Make sure they were done.
• Transmission complaints are common on diesels (about 1 in 8).

Duramax LML fuel pump (CP4.2)

44 diesel complaints mention the fuel pump, CP4, low fuel pressure or code P0087, and owners describe sudden stalling and no-starts. Like Ford's 6.7L of the same era, 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 for a full fuel system replacement. There was no recall for these years.

When buying: ask whether the pump has been replaced or upgraded (some owners switch to a different pump design as prevention) and for fuel filter records. A scan for low fuel pressure codes is worth doing.

DEF and NOx sensors

DEF heater failures that put the truck into reduced power are commonly reported, and 2011 trucks are known for NOx sensor problems that trigger "Poor DEF quality" messages. Ask whether the emissions system has been removed ("deleted"), which can cause inspection and legal problems.

Airbag recalls

Airbags come up in about 3 in 10 complaints (166 of 543 mention air bags, inflators or Takata), often from owners waiting on recall parts. Passenger airbag inflator recalls cover certain 2011–2014 trucks, split by model year and region (21V050000, 21V051000, 21V053000 and 21V054000). Check that they're completed.

Other things to check

• Steering wear: idler arms, pitman arms and tie rods are frequently replaced on these trucks. Check for play and clunks.
• Cracked dashboards are commonly reported (about 90 complaints).
• Transmission: 49 diesel complaints (about 1 in 8) and 8 gas complaints mention the transmission.
• Certain 3500s with dual fuel tanks were recalled because a stuck fuel level sensor can let the rear tank overfill the front tank (recall 17V664000).
• Rust on rocker panels, cab corners, frame and brake lines.

Before you buy

• Check open recalls at nhtsa.gov/recalls with the VIN.
• Get a pre-purchase inspection from a diesel shop, including a scan for fuel pressure and DEF codes.
• Bring our used truck inspection checklist.