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Turbo & VGT codes — quick reference

FMI (Failure Mode Identifier) — Quick Reference

How to Read a Code

Cummins INSITE shows FC (Fault Code) numbers like FC2387.
Generic scan tools show SPN + FMI like SPN 641 FMI 7.
PACCAR DAVIE4 shows P-codes like P0045.
SPN = what component has the fault (e.g. SPN 641 = VGT actuator).
FMI = how it is failing (see table above).
Multiple active codes? Address the lowest-numbered code first — it is most often the root cause.