The 6.6L V8 LML turbodiesel Duramax engine Bosch CP4 fuel pump failed. U.S. diesel fuel does not provide adequate lubrication for the CP4 fuel pump. The lack of lubrication led to internal fuel pump damage and resulted in metal shavings that damaged the pump, the fuel system, and the GM Duramax engine as well. There was no warning lamps, messages or other symptoms of the problem prior to the failure.

- Lincoln, MA, USA

On August 5, 2023 I was driving south on I75 in the Flint, Michigan area With no warning my engine shut down. High Pressure Fuel Pump (Diesel Truck) imploded and pumped metal shavings through the entire fuel system, Fuel Rails, and Injector system. Vehicle is currently being repaired. Repair consist of, Removal of the gas tank and completely clean. Flush and clean the entire fuel system, Remove injectors and replace with new. Replace old fuel Pump with new.

- Grand Blanc, MI, USA

had to replace fuel pump at 60000 miles and had to have aftermarket replacement because dealership has been on back order for months. it was fine when i drove it last then 4 hours later won-??t start.

- Three Rivers , MI, USA

I was driving home from work on a busy road that had road construction and my truck without warning just died as if it ran out of fuel. I had it diagnosed and it-??s the MP4 injection pump that went bad. Very common in this year it-??s a minimum of$9500. To replace the entire fuel system. It could have caused me to have an accident. And GM is aware of the injection pumps going bad. The MP4 pumps are designed for vehicles in European countries not the USA. Ford and Dodge have class action lawsuits against them for this faulty system.

- Copperopolis, CA, USA

I purchased 2016 Chevrolet 2500 HD from the dealership. The truck I bought had the CP4 high-pressure fuel injection pump, which comes standard in all GM-manufactured 2011-2016 6.6L Duramax diesel vehicles such as the Chevy Silverado and GMC Sierra, and it is incompatible with U.S. diesel fuel. The pump was originally designed for use in Europe, where the diesel fuel is "dirtier, " or more lubricious, than that of the U.S. Because of the heightened pressure that the CP4 exerts in order to increase fuel efficiency, it causes the pump to disintegrate on itself, as the pump's internal metal parts rub against one another generating friction such that metal shavings wear off and are dispersed throughout the high-pressure fuel injection system. This process begins from the very first crank of the Duramax engine. Once these metal shards have sufficiently contaminated the high-pressure fuel injection system, the CP4 fuel pump will suddenly and catastrophically fail -?" oftentimes while the vehicle is in motion -?" and become unable to restart. I-??m now looking at a $11,000 repair bill. GM knowingly sold a truck with defective parts.

- Chino Hills, CA, USA

I am on a cross country trip and the vehicles engine light came on, I pulled into a Chevy dealer for service. Chevy dealer claims the part needed for repair called an ECM module, (I.e. computer) is not available and it is not being produced because of a defect in design. The vehicle has been with a Chevy dealer for 10 days. I am 1100 miles from home and General Motors has refused to give me a loaner to drive back to Kansas City. In talking with the diesel technicians at two of the dealers, they claim this is a widespread problem that GM is trying to hide.

- Leawood, KS, USA

Vehicle just shut off while in operation then would turn over but no start. Vehicle was towed to dealership and was advised fuel pump failed and would be covered under warranty. Luckily vehicle was stationary but was in prepartion for a vacation pulling our 5th wheel camper. From researching since this incident, I've been in contact with several individuals who have had this part fail not only while moving but have had it happen twice. Even the service advisor's acknowledge that this part is a known failure item and will happen again. Service department had vehicle for 2 weeks.

- Southaven, MS, USA