This Doser fuel line pressure sheet documents Detroit SPN 3480 FMI 2, a low reading that carries a 10 percent derate. It moves from fuel-fault triage and leak inspection to live pressure monitoring and regeneration. Follow the numbered steps.
Official document details
| Brand | Detroit |
|---|---|
| Model coverage | DD Series (EPA 2007-Current); also filed under Series 60 (DDEC VI – EPA 2007) |
| System / Group | DTCs — Hydrocarbon (HC) Doser Fuel Line Pressure Low |
| Fault code | SPN 3480 / FMI 2 |
| Source | www.TruckFaultCodes.com (© 2017) |
| Pages | 4 |
| File size | 0.3 MB |
| Format | |
| Language | English |
Doser fuel line pressure diagnostic guide
After the vehicle is safed and the diagnostic tool connected, fuel system faults are repaired first and the doser block and injector fuel lines are inspected for leaks. Once the cutoff reaches 100 percent, the technician monitors compensation pressure against the charted Gen 1 and Gen 2 windows in absolute terms, roughly gauge pressure plus 14.5 psi. The reading decides between a low-pressure fuel test, a new compensation sensor and a new metering unit. A parked regeneration and retained log complete the job.
Document table of contents
- Fault code identification: SPN 3480, FMI 2
- Description, monitored parameter and 10 percent derate
- Fuel-fault triage and external leak inspection
- Live compensation pressure monitoring by generation
- Parked regeneration and verification
Applicable truck models
This procedure applies to Detroit DD Series engines built for EPA 2007 and later, covering all model years (EPA07, EPA10 and GHG14) as printed on the document cover, and the identical SPN/FMI sheet is also filed under Detroit Series 60 (DDEC VI, EPA 2007). Confirm the emissions platform on your truck and cross-check the connector and pin numbers against the official Detroit engine support site before making any repair.
Who needs this fuel line pressure manual
A diesel technician on any Detroit DD model year with a low pressure complaint uses this sheet to read compensation pressure correctly in absolute terms and choose the right repair by system generation.
The full 4-page PDF is available in the DiagTechPro manuals library; a free account is required to download.
Related manuals library
