Fuel rail pressure too low
The reading is real and it is dangerously low. Low oil pressure, low coolant level and low rail pressure land here. Treat it as a real condition until proven otherwise.
SPN 94 — Fuel rail pressure too low
SPN 94 is the parameter the ECM is flagging on PACCAR, CAT, Detroit, International, MERCEDES, Volvo, Mack, Cummins engines. The FMI that comes with it tells you how it failed. Each failure mode below has its own causes and its own test order — do not treat them as the same repair.
Fuel pressure low
The reading is real and it is dangerously low. Low oil pressure, low coolant level and low rail pressure land here. Treat it as a real condition until proven otherwise.
Fuel delivery pressure below normal
The reading is real and it is dangerously low. Low oil pressure, low coolant level and low rail pressure land here. Treat it as a real condition until proven otherwise.
Fuel delivery pressure below normal
The reading is real and it is dangerously low. Low oil pressure, low coolant level and low rail pressure land here. Treat it as a real condition until proven otherwise.
Fuel delivery pressure below normal
The reading is real and it is dangerously low. Low oil pressure, low coolant level and low rail pressure land here. Treat it as a real condition until proven otherwise.
Fuel delivery pressure below normal
The reading is real and it is dangerously low. Low oil pressure, low coolant level and low rail pressure land here. Treat it as a real condition until proven otherwise.
Fuel delivery pressure below normal
The reading is real and it is dangerously low. Low oil pressure, low coolant level and low rail pressure land here. Treat it as a real condition until proven otherwise.
Fuel delivery pressure below normal
The reading is real and it is dangerously low. Low oil pressure, low coolant level and low rail pressure land here. Treat it as a real condition until proven otherwise.
Fuel delivery pressure sensor circuit voltage above normal
The signal wire is seeing more voltage than the circuit should ever produce — usually the signal wire touching battery power or the 5 V reference.
Fuel delivery pressure sensor circuit voltage above normal
The signal wire is seeing more voltage than the circuit should ever produce — usually the signal wire touching battery power or the 5 V reference.
Fuel delivery pressure sensor circuit voltage above normal
The signal wire is seeing more voltage than the circuit should ever produce — usually the signal wire touching battery power or the 5 V reference.
Fuel delivery pressure sensor circuit voltage above normal
The signal wire is seeing more voltage than the circuit should ever produce — usually the signal wire touching battery power or the 5 V reference.
Fuel delivery pressure sensor circuit voltage above normal
The signal wire is seeing more voltage than the circuit should ever produce — usually the signal wire touching battery power or the 5 V reference.
Fuel delivery pressure sensor circuit voltage above normal
The signal wire is seeing more voltage than the circuit should ever produce — usually the signal wire touching battery power or the 5 V reference.
Fuel delivery pressure sensor circuit voltage above normal
The signal wire is seeing more voltage than the circuit should ever produce — usually the signal wire touching battery power or the 5 V reference.
Fuel delivery pressure sensor circuit voltage above normal
The signal wire is seeing more voltage than the circuit should ever produce — usually the signal wire touching battery power or the 5 V reference.
Fuel delivery pressure low
Real reading, slightly low. Early warning stage.
The reference is free. The diagnosis is Pro.
Every SPN and FMI page on this site stays open — no account needed. Pro members can take the code into Truck Commander Pro AI with the VIN, symptoms and photos, keep per-truck history, and print a work order. $9.99 a month.