SPN 1073 FMI 3 is the Detroit DD Series fault-code troubleshooting sheet that documents a Jake Brake Stage 2 circuit failed high condition on the Motor Control Module engine platform. This 1-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
| Brand | Detroit |
|---|---|
| Model coverage | Detroit DD Series (EPA 2007-Current) |
| System / Group | DD Series (EPA 2007-Current) / DTCs |
| Fault code | FMI 3 under SPN 1073 (ALL YEARS) |
| Source | Detroit fault-code literature via TruckFaultCodes.com, © 2017 |
| Pages | 1 |
| Format | |
| Language | English |
SPN 1073 FMI 3 fault description
This single-page sheet gives the direct repair for a stage-2 engine-brake circuit that has failed high. The corrective action is to repair the short to battery power between pin 1 on the Jake Brake solenoid and pin 32 on the Motor Control Module (MCM) 120-pin connector. Because the failure mode points to voltage being applied where it should not be, the sheet is a concise wiring-repair reference rather than a multi-step decision tree, aimed at technicians who have already confirmed the code with a diesel diagnostic tool and need the exact pins involved.
The SPN 1073 FMI 3 sheet identifies the following likely causes and check points:
- Short to battery power on the stage-2 Jake Brake circuit
- Voltage present between pin 1 of the solenoid and pin 32 of the MCM
Document table of contents
- Fault code identification
- Circuit short-to-power repair between the solenoid and the MCM
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 1073 FMI 3 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 1-page PDF of this procedure is available in the DiagTechPro manuals library; a free account is required to download.
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