SPN 4193 FMI 2 is the Detroit diesel fault code documented in this coolant inlet temperature not plausible troubleshooting guide for DD Series (EPA 2007-Current) engines. This 2-page PDF explains the monitored condition, the enabling parameters and the step-by-step checks a technician follows to confirm and repair the code. It is part of the Detroit DD Series diagnostic trouble code (DTC) library and follows the standard monitored-parameter, enabling-conditions and troubleshooting-step layout used across the Detroit fault-code set.
Official document details
| Brand | Detroit (Detroit Diesel) |
|---|---|
| Model coverage | DD Series (EPA 2007-Current); cross-referenced for Series 60 (DDEC VI – EPA 2007) |
| System / group | DD Series (EPA 2007-Current) / DTCs |
| Fault code | FMI 2 under SPN 4193 — Coolant Inlet Temperature Not Plausible |
| Emissions level | EPA10, GHG14 |
| Pages | 2 |
| File size | 0.3 MB |
| Format | |
| Language | English |
SPN 4193 FMI 2 troubleshooting steps
- Monitored parameters are the coolant inlet and coolant outlet temperature sensors; enabling conditions include engine speed 500-2500 RPM and coolant temperature above 65°C.
- Check for and repair any cooling-system issues first.
- Warm the engine to operating temperature 185°F (85°C); if it will not reach it, replace the engine coolant thermostat.
- Disconnect the inlet and outlet coolant sensors and inspect the connectors for bent, spread or corroded pins.
- Check coolant-sensor resistance against the chart and replace any sensor out of range.
Applicable truck models and engines
This document applies to Detroit DD Series (EPA 2007-Current) engines and covers the plausibility check between the inlet and outlet coolant temperature sensors. The procedure is published in Detroit Power Service Literature and drawn from the Detroit diesel fault-code set; always confirm the latest revision through the official Detroit engine support site.
Who needs this SPN 4193 FMI 2 manual
Fleet technicians and workshop owners use this guide to resolve an implausible inlet-versus-outlet coolant reading on a DD Series engine. Reading the full procedure before touching the harness keeps the diagnosis on the documented path and avoids replacing good parts.
The full PDF is available in the DiagTechPro manuals library, where a free account is required to download.
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