*Median odometer reading when the problem happened, where owners gave one. One complaint can name several problem areas.
Unknown or other
My HMI was "bricked" when onstar pushed an incompatible update when I changed the service plan. While driving the screen has intermittently turned off and on causing temporary unexpected loss of navigation functions, Bluetooth connectivity, and use of the back up camera. This causes a safety issue as the unexpected loss of display and connectivity has caused me to be unable to continue using hands free features during operation, and to no longer view behind the vehicle during entirety of backing. When I contacted OnStar support I was instructed to perform some troubleshooting and was then referred to the Connection Center Team. The CCT representative told me that my hardware was outdated…
Jun 25, 2026Electrical system › Horn
The contact owns a 2016 GMC Sierra 2500. The contact stated that the horn was inoperable. The contact became aware of the failure when the horn failed to sound while locking the vehicle with the key fob. Upon investigation, the contact discovered that there were no recalls on the VIN related to the failure. Neither the dealer nor the manufacturer was notified of the failure. The vehicle was not repaired. The failure mileage was approximately 150,000.
Nov 23, 2025 · 150,000 milesFuel/propulsion system
CP4 injection pump failure while driving nearly causing vehicle collision.
Aug 1, 2025Fuel/propulsion system
The CP4 pump failed while driving causing vehicle to stall. Upon failure, lost power to steering. Luckily we were on an access road for a rest area and not yet on the interstate. This resulted in a 14.5 thousand repair. No prior warning to pump failure. GM has recently settled a class action related to this pumps failure and has never recalled trucks with this pump to avoid failure.
Jun 5, 2025Fuel/propulsion system
My vehicles High Pressure Fuel Pump failed causing the vehicle to shutoff while driving. In addition, due to the engine shutting down while driving, the power steering quit working causing me to not be able to steer the vehicle. Thank you
Jun 6, 2025Fuel/propulsion system
My 2016 GMC Sierra 2500 with a 6.6-liter Duramax diesel V8 engine suffered a complete engine shutdownâan issue that is both hazardous and expensive to repair. Fortunately, mine failed in a parking lot. No warning lights or symptoms were present. Failure is instantaneous and can occur any time rendering the vehicle inoperable on high-speed highways, Intersections, etc. Failure always leaves vehicle occupants stranded, creating an unsafe and dangerous situation. My vehicle was towed to a GMC dealer. Repair costs could be as high as $15,000. The 6.6-liter Duramax diesel V8 engine is equipped with a Bosch âCP4â high-pressure fuel pump. These pumps are unreasonably fragile and prone to…
Apr 22, 2025Engine
Motor stopped dead while driving on a local Interstate Hwy. Was able to negotiate the truck out of traffic without crashing. Not an easy thing to do in speeding rush hour traffic. Had the truck towed to a reputable repair shop and discovered the CP4 fuel pump had failed and shattered throughout the fuel system. Repairs in the amount of $13,520.30 incurred to get the truck back in service. The attached invoice includes $167.87 for other maintenance not related to the CP4 fuel pump repair. This is a known problem and safely hazard. A class action suit settlement is related to the CP4 fuel pump against multiple truck manufacturers. # [XXX] and can be found at [XXX] . Minnesota is not included…
Feb 27, 2025Fuel/propulsion system
My high pressure fuel pump, cp4, went out with no warning while driving causing me to lose power. Was able to bring truck to stop safely but was stuck in middle of roadway.
Aug 22, 2024
Owner complaints are submitted to NHTSA by the public and are not verified. Shown as filed (NHTSA removes personal details); long reports are shortened.