SPN 1077 FMI 15 is the Detroit DD Series fault-code troubleshooting sheet that documents internal or external leakage of the high pressure fuel system, set when the MCM detects a leakage rate greater than 100 l/h on the Motor Control Module engine platform. This 3-page reference reproduces the fault-code identification and the factory decision tree so a technician can diagnose the concern before replacing parts.
Official document details — SPN 1077 FMI
| Brand | Detroit |
|---|---|
| Model coverage | Detroit DD Series (EPA 2007-Current) |
| System / Group | DD Series (EPA 2007-Current) / DTCs |
| Fault code | FMI 15 under SPN 1077 (ALL YEARS) |
| Source | Detroit fault-code literature via TruckFaultCodes.com, © 2017 |
| Pages | 3 |
| Format | |
| Language | English |
SPN 1077 FMI 15 fault description
This code carries no limp-home fault reaction. The procedure has the technician check for a companion 1077/14 code first, then perform an Automatic Fuel System Integrity Check and evaluate the rail-pressure bleed-off time against a 35-second threshold. It continues through internal and external high pressure leak tests, Idle Speed Balance checks, injector capping with J-48704, Pressure Limiting Valve flow testing and amplifier or needle return measurements, ending at high pressure fuel pump replacement when leakage cannot be isolated to an injector or valve.
The SPN 1077 FMI 15 sheet identifies the following likely causes and check points:
- External leakage between the high pressure pump and fuel injectors
- High pressure pump pumping elements
- Fuel injector amplifier or needle leakage
- Pressure limiting valve internal leakage
Document table of contents
- Description and monitored conditions
- Check for multiple codes
- Automatic Fuel System Integrity Check
- Rail pressure bleed-off evaluation
- Injector capping and PLV flow test
Service tools referenced
- J-48704 high pressure fuel rail caps
Applicable truck models
This troubleshooting sheet applies to Detroit DD Series engines built from EPA 2007 to current that use the Motor Control Module (MCM) and Common Powertrain Controller architecture. Confirm the engine’s emissions family and calibration against the manufacturer’s official documentation at the Detroit engine website before repairs.
Who needs this SPN 1077 FMI 15 manual
Heavy-duty diesel technicians, fleet shops and mobile mechanics who retrieve this code on a Detroit DD engine need this manual to follow the factory decision tree instead of guessing. It is written for anyone using DDDL or an equivalent diesel diagnostic tool who wants the exact test values before condemning a component.
The full 3-page PDF of this procedure is available in the DiagTechPro manuals library; a free account is required to download.
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