SPN 3556 EPA07 regen is documented in this Detroit DD Series fault code reference PDF, which covers the Check For Regen Temperature Out Of Range Low condition on Detroit engines. The 5-page document lists the fault description, the step-by-step troubleshooting sequence and the connector measurements a technician uses to confirm the repair.
Official document details
| Brand | Detroit |
|---|---|
| Model coverage | Detroit DD Series (EPA 2007-Current) engines on the EPA07 emissions platform |
| System / group | DD Series (EPA 2007-Current) / DTCs |
| Diagnostic code | FMI 1 / SPN 3556 |
| Year / revision | Source dated 2017 |
| Pages | 5 |
| File size | 0.4 MB |
| Format | |
| Language | English |
Document table of contents
- Fault code identification: SPN 3556, FMI 1
- Regen temperature out of range low
- Exhaust and V-band clamp inspection
- High idle regeneration monitoring
- Doser fuel line and injector checks
- Repair verification and support contact
Applicable truck models and engines
This fault code applies to Detroit DD Series (EPA 2007-Current) engines on the EPA07 emissions platform, and the DiagTechPro library also files it under the Series 60 (DDEC VI, EPA 2007) DTC set. The diagnostic references the aftertreatment doser and temperature sensor circuits used on these Detroit powertrains. See the manufacturer’s Detroit official website for current engine specifications and dealer support.
SPN 3556 EPA07 regen troubleshooting overview
The routine starts by checking for related codes, then inspecting the exhaust system and aftertreatment device V-band clamps for leaks. The engine is run at 1200 rpm and aftertreatment temperatures are compared within 45°F of each other. A high idle regeneration is used to monitor DOC outlet temperature against the DOC Model Delay, doser fuel line pressure is checked above 40 psi, and the doser fuel line and injection valve are inspected for kinks and carbon. The manual lists the Detroit Customer Support Center number for cases needing further help.
Who needs this SPN 3556 EPA07 regen manual
Detroit-certified technicians, independent truck repair shops and fleet maintenance teams will use this reference to follow the factory diagnostic sequence with a diesel diagnostic tool before replacing any control module or sensor.
The full PDF is available in the DiagTechPro manuals library; a free account is required to download it, alongside the related Detroit Power Service Literature.
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