The Detroit DEF pump flow document is a Detroit fault code reference that explains a non Diesel Exhaust Fluid (DEF) flow situation on the aftertreatment dosing system, published for DD Series engines under SPN 5435 FMI 7 (GHG14). It gives workshop technicians the diagnostic sequence used to confirm the condition and return the truck to service, sourced from Detroit Power Service Literature.
Official document details
| Brand | Detroit (Detroit Diesel) |
| Model coverage | DD Series (EPA 2007-Current) and Series 60 (DDEC VI) |
| System / Group | Diagnostic Trouble Codes (DTCs) |
| Fault code | SPN 5435 / FMI 7 |
| Emissions family | GHG14 |
| Pages | 2 |
| File size | 0.3 MB |
| Format | |
| Language | English |
Document table of contents
- Fault code identification — SPN 5435 / FMI 7
- Fault description and monitored parameters
- DEF pump harness inspection
- DEF pump 4-pin to ACM2.1 pinout
- SCR ADS self-check and pump replacement
Troubleshooting the Detroit DEF pump flow code
The routine confirms SPN 4374 codes are not active, then inspects the DEF pump harness and connector for chafing, bent, spread or corroded pins using the 4-pin to ACM2.1 pin table. The DEF pressure line is disconnected into a DEF-safe container and the SCR Airless Dosing System self-check is run while monitoring flow; if no flow is seen and pump speed stays below 600 rpm, the DEF pump module is replaced and repairs are verified with the self-check.
Applicable truck models and engines
This diagnostic sheet applies to Detroit DD Series diesel engines built to EPA 2007 through current emissions standards, and the covered fault also appears on Series 60 (DDEC VI) applications listed in the source. Confirm the exact engine family and calibration against the vehicle before making repairs, and cross-check the specifications on the official Demand Detroit website.
Who needs this Detroit DEF pump flow manual
Heavy-duty truck technicians, fleet maintenance staff and workshop owners diagnosing SPN 5435 FMI 7 with a diesel diagnostic tool will use this sheet to follow the correct steps rather than replacing parts by guesswork.
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