SPN 4193 FMI 3 is the Detroit diesel fault code documented in this engine coolant inlet temperature circuit failed high 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 3 under SPN 4193 — Engine Coolant Inlet Temperature Circuit Failed High |
| Emissions level | EPA10, GHG14 |
| Pages | 2 |
| File size | 0.2 MB |
| Format | |
| Language | English |
SPN 4193 FMI 3 troubleshooting steps
- The monitor is always enabled with a typical duration of 2 seconds and lights the MIL and CEL dash lamps.
- Disconnect the engine coolant inlet temperature sensor, turn the ignition on and inspect the harness for bent, spread or corroded pins.
- Measure the voltage across pins 1 and 2 of the sensor harness connector: 2.8 to 3 volts means replace the sensor.
- If voltage is low, measure between pin 2 and ground and repair the wire to MCM 120-pin connector pin 55 or pin 80 as indicated.
- If voltage is above 3 volts, repair the short to power on MCM pins 77, 80, 108 or 110, or repair the open in the shared temperature-sensor supply.
Applicable truck models and engines
This document applies to Detroit DD Series (EPA 2007-Current) engines and covers the engine coolant inlet temperature sensor and its MCM wiring. 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 3 manual
Fleet technicians and workshop owners use this guide to trace a circuit-high signal to the sensor, the harness or the MCM connector pins. 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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