When diesel injector pumps fail, the results can be catastrophic to the entire fuel system. The repairs may involve more than an injector pump replacement. Failures often fall under a category of a contaminated or non-contaminated fuel system. When the contamination is metal, several thousand dollars in repair costs can be incurred.
High Pressure Fuel Pump Failure
Chrysler/Stellantis has responded to a NHTSA 23V-263 recall involving the High Pressure Fuel Pump, commonly referred to as the injector pump. Failure of the pump may result in the introduction of metal contaminants/debris into the fuel system resulting in fuel starvation. When this occurs, the symptoms may include:
The questionable injector pump is Mopar part #68501449AA.
Diesel engines affected by this injector pump recall include the following:
Vehicles listed in this NHTSA notice include the following:
Stellantis TSB 14-010-25 dated June 24, 2025 was issued to communicate the process to be followed when checking for fuel system contamination, prior to replacing any of the components on the fuel line such as fuel filters. In addition to the models listed above, this TSB reflects additional year models that could be affected. Those applications include:
Verification can be confirmed by submitting the VIN number to the dealer or NHTSA.
Failed Injector Pumps
Injector pump failures resulting in metal contaminants being dispersed throughout the fuel system will require some major service procedures or component replacement, based on the level of contamination, to include the following:
Vehicles delivered to the dealer in good running condition with no evidence of system contamination will only receive a new injector pump.
Caution: When checking for high pressure fuel leaks use extreme caution. Fuel pressure from the injector pump to the fuel injectors may be as high as 29,000 psi. At this pressure, fuel can penetrate the skin resulting in injury or death. High pressure leaks should be checked with a piece of cardboard, the same way you would check for high pressure hydraulic fluid leakage.
GM Duramax Injector Pump Failure
GM used the Bosch CP3 injector pump on the 6.6L Duramax for most applications from 2001-2010 without any quality issues. GM changed to the Bosch CP4 injector pump on the 6.6L Duramax (RPOs LML, LGH) applications from 2011-2016. The change was likely due to the CP4 injector pump being lighter and a reduction in production cost. Due to a high failure rate with this design pump, GM changed to the Denso style injector pump in 2017.
Repair cost due to failed CP4 injector pumps ranged from $10,000 to $18,000. The repair cost involved replacing the injector pump, fuel injectors, high- pressure and return fuel lines. The fuel tank and fuel filter housing required cleaning and a new fuel filter installed.
Bosch CP4 Additional Applications
Other vehicle manufacturers, including Ford and Dodge, have used the same Bosch CP4 injector pump.
Ford used the injector pump on the Power Stroke 6.7L from 2011-2021.
Dodge went to the CP4 injector pump from 2019- 2020 on the Ram 2500/3500 Pickups and the Ram 3500/4500/5500 Chassis Cabs with the 6.7L Cummins engine. Dodge recalled approximately 222,410 vehicles and replaced the injector pumps with the Bosch CP3 unit due to high failure rates of the CP4 injector pump.
Fuel Quality And Lubricity
Reports indicate the CP4 injector pump was not designed to operate on diesel fuel produced in the US. The low sulfur content of the fuel produced in the US does not provide sufficient lubrication to protect the system. The reduction of sulfur in the fuel from 500 PPM to 15 PPM (parts per million) has resulted in some major and very expensive repairs.
To comply with the stringent emission standards the reduction in the sulfur content of the fuel was mandated. The refining process by which this is achieved can alter the lubricating properties in the fuel, affecting the lubricity of the fuel. Lubricity is a measure of the fuel’s ability to provide sufficient lubrication to prevent premature wear of the fuel system components and moving parts within the injector pump. Degradation within the system can result in premature wear and metal particles being dispersed throughout the fuel system, resulting in a catastrophic failure and costly repairs.
In addition, the operating pressures of the Bosch CP4 injector pump may result in aeration of the fuel within the pump, promoting metal-to-metal contact and accelerated wear, flooding the system with metal particles.
Scheduled Maintenance
While not related to the failures illustrated in this Tech Tip, some basic maintenance will prevent costly repairs. Neglecting routine maintenance on a gas burner may result in poor performance, loss of fuel economy and high emission output. Let the same service go on a turbo-charged diesel engine and you are in store for some expensive repairs, maybe even a turbocharger or engine replacement. While most shops leave the routine maintenance request up to the customer, a little awareness from you could save the customer a lot of expense in needless repairs.
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