SPN 411 FMI 2 is a Detroit fault code reference sheet that documents the Exhaust Gas Recirculation (EGR) delta P sensor is out of calibration diagnostic for DD Series engines built to EPA 2007 and later emissions standards. This single-topic page reproduces the factory-style test order Detroit dealers and independent shops follow for the EGR delta P sensor and its circuit, from confirming related codes through to the final repair decision.
Official document details
| Brand | Detroit |
| Model coverage | DD Series (EPA 2007-Current) |
| System / group | Diagnostic Trouble Codes (DTCs) |
| Suspect Parameter Number | 411 |
| Failure Mode Identifier | 2 |
| Emissions revision | GHG14 |
| Source | Detroit fault code sheet (© 2017, www.TruckFaultCodes.com) |
| Pages | 4 |
| File size | 0.27 MB |
| Format | |
| Language | English |
SPN 411 FMI 2 troubleshooting steps
The sheet opens with the code’s monitor description: monitored parameter EGR delta pressure, enabling condition coolant temperature above 176°F, dash lamps MIL and CEL, and a 25% engine derate. The published checks then run in order:
- With the ignition ON, use the diesel diagnostic tool to monitor EGR delta P voltage (pin 109) and confirm it is between 0.55 and 0.83 volts.
- Remove the delta P sensor from the mounting pad and recheck the voltage; inspect the EGR delivery pipe pressure ports for blockage and clean the venturi pipe if needed.
- Inspect the sensor harness connector for bent, spread or corroded pins and repair as required.
- Disconnect the Motor Control Module (MCM) 120-pin connector and measure the sensor pin-to-pin and pin-to-ground resistances to isolate shorts; if all pass, replace the sensor and run the re-calibration routine.
Applicable truck models
This code applies to Detroit DD Series diesel engines (EPA 2007 to current) and, for the shared driveline codes, to Series 60 (DDEC VI) installations that use the same Common Powertrain Controller and Motor Control Module architecture. Coverage is defined by the engine and control-module configuration rather than the truck badge, so confirm the exact build against the current model line on the Detroit Diesel official website.
Who needs this SPN 411 FMI 2 manual
This SPN 411 FMI 2 manual is written for diesel technicians and DD Series fleet owners who are diagnosing an EGR delta P sensor that reads out of calibration and want the exact Detroit test order before ordering parts. Following the documented sequence keeps unnecessary sensor and module replacements to a minimum.
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