Nine real diagnostic scenarios — low system pressure, a fire pump failing churn, sprinkler MIC corrosion, kitchen hood false discharge, clean agent integrity failures, foam degradation, dry pipe trip-time failure, and waterflow nuisance tripping — worked as Symptoms → Diagnosis → Testing → Resolution.
A fire suppression system that was designed and installed correctly can still develop real problems years into service — a closed valve nobody re-opened, corrosion working invisibly inside wetted pipe, a fire pump that quietly stopped meeting its rated performance. This module treats diagnosis as a structured discipline rather than guesswork, then works through nine real failure scenarios end to end: what symptom actually gets reported, how a competent engineer or technician narrows the cause, what test confirms it, and what the correct resolution actually is.
The scenarios span every system type covered earlier in this program — sprinkler, standpipe, fire pump, kitchen hood, clean agent, and foam — and this module assumes the design content from those earlier modules plus the ITM frequencies from Module 16, which is exactly where most of these failure patterns first get caught in the field.