Diesel Fault Code Finder
Decode fault codes, SPN/FMI pairs, and flash codes for Cummins, Duramax, Power Stroke, PACCAR, Detroit Diesel, and CAT engines. Causes, diagnostics, and real-world fixes -- free.
2,010 diesel codes · 5 engine families · J1939 SPN/FMI · Free, no account needed
Browse by Engine
Cummins
ISX, X15, ISB 6.7L, ISL, ISC -- fault codes & SPN/FMI lookups.
Duramax
LB7, LLY, LBZ, LMM, LML, L5P -- GM / Chevy & GMC diesel codes.
Power Stroke
7.3L, 6.0L, 6.4L, 6.7L -- Ford Super Duty diesel faults.
PACCAR
MX-11, MX-13 -- Kenworth, Peterbilt, DAF engine codes.
Detroit Diesel
DD13, DD15, DD16 -- Freightliner & Western Star codes.