Diesel · Reference Tool

Detroit DD13 / DD15 Fault Code Lookup

0+ real Detroit Diesel DD13, DD15 and DD16 (GHG14 / GHG17 / GHG21) fault codes. Search by SPN, FMI, or symptom. See likely causes and the first diagnostic checks a dealer tech would run.

Master this platform end to end

Full DD13/DD15 course with wiring, aftertreatment, case studies AND module quizzes — included with Pro.

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Practice Mode

Step-by-step diagnostic scenarios for common DD13/DD15 faults. Choose your next step, get instant feedback, see the fix at the end.

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Wiring & pinout cheat sheet (PDF)

MCM, CPC, ACM pinouts · J1939 bus · 20 DVOM tests with pass criteria.

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Case-study diagnostic worksheet (PDF)

Print one per case study. Intake · fault table · DVOM tests · circuit sketch · root-cause & sign-off.

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Stop guessing

Diagnose it right the first time

The full Detroit DD13 & DD15 Diagnostics & Fault Code Mastery course walks wiring diagrams, SPN/FMI logic, DPF regen strategy, DEF/SCR troubleshooting, and real case studies — with module quizzes and a final exam.

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