John Deere Fault Code
Free · no signupSPN 157 FMI 1
Extreme Power Loss / Derate
System
Fuel System
Symptom
Extreme Power Loss / Derate
Diagnosis & fix steps
LOGIC: Fuel Rail Pressure Below Range.
ACTION: Check the suction side for air leaks or a plugged primary fuel filter.
Red Seal field insights
Specs: Rail pressure vs. Commanded pressure difference >20MPa.
FIX: If filters are new, the high-pressure pump (HPCR) is failing.
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