Failure mode - Cummins 6.7L ISB Diesel (Ram HD, 2019+ generation)

CP4 high-pressure fuel pump failure and fuel system contamination (2019-2020 6.7)

Reliability tier: verified - verify before ordering, see /disclosure/

Symptoms

sudden loss of power and stall, often with no warning or after a 'Service Exhaust System' type message; may not restart
codes P0087 (rail pressure too low), P008A (low-pressure side too low), P0201-P0206 (injector circuits); engine will not start
metal debris in the fuel filters once the pump has come apart

Compare with the other causes of the same sign on this engine: hard start, long crank or no-start (3 causes) · stalls or dies while driving · loss of power, limp mode or derate (4 causes) · metal in the fuel filter or oil

Root cause

2019-2020 Ram HD trucks with the 6.7 Cummins use a Bosch CP4-style high-pressure pump that may fail and stall the engine (safety recall 21V-880, FCA Y78, about 222,000 vehicles). A failed pump sends debris through the fuel system; Ram's bulletins 18-099-22 and 18-054-21 cover inspection for pump failure and contamination, fuel system cleaning and a fuel system kit. Under Y78 dealers replace the pump with a CP3.3-style pump (bulletin 14-008-22), update the PCM software and replace other fuel system parts as needed.

Diagnosis

check the VIN for recall 21V-880 / Y78 first
on a stall or no-start, inspect the fuel filters for metal before replacing parts
a CP3.3 pump looks and sounds different from the CP4; bulletin 14-008-22 explains the identification differences

Fixes

recall Y78: CP3.3-style pump, PCM update and fuel system parts as needed, free at a Ram dealer ()

hpfp - more than one option: 6.7L Cummins HPFP Flow Control Valve (Mopar 68444374AA, 2019-2020), 6.7L Cummins Fuel Injection Pump Module Kit (Mopar 68503520AA, 2019-2020)

after a failure: fuel system cleaning and contamination kit per Ram bulletin 18-099-22 ()

Prevalence

very-common