The DEF system circuit low fault sheet is the official Detroit DD Series diagnostic for a DEF supply circuit that failed low, stored under SPN 3361 FMI 4 for GHG14 calibrations. It records the monitored parameter DEF Dosing Unit Voltage, dash lamps None, engine reaction Derate 25%, verification by SCR ADS Self-Check, exactly as published by TruckFaultCodes.com (© 2017).
Official document details
| Brand | Detroit |
|---|---|
| Model coverage | Detroit DD Series diesel engines (EPA 2007-current) |
| System / Group | DD Series (EPA 2007-Current) / DTCs |
| Fault code | SPN 3361 / FMI 4 |
| Fault condition | Diesel Exhaust Fluid (DEF) System Circuit Failed Low |
| Monitored parameter | DEF Dosing Unit Voltage |
| Dash lamps | None |
| Engine reaction | Derate 25% |
| Verification | SCR ADS Self-Check |
| Emissions calibration | GHG14 |
| Source / Publisher | TruckFaultCodes.com |
| Year / Revision | 2017 |
| Pages | 2 |
| File size | 0.3 MB |
| Format | |
| Language | English |
Document table of contents
- Fault code identification: SPN 3361, FMI 4
- Description and monitored parameter
- Typical enabling conditions
- Troubleshooting steps
- Component inspection and repair verification
DEF system circuit low troubleshooting steps
The sheet checks DEF Dosing Unit voltage after dosing is enabled and disabled, has the technician inspect the supply circuit for a short to ground, and verifies the repair with the SCR ADS Self-Check.
Applicable truck models
This code sheet applies to trucks powered by Detroit DD Series diesel engines built to the GHG14 emissions calibration; always match the SPN 3361 FMI 4 listing to the vehicle’s own engine family before repair. Confirm the emissions family on the vehicle emissions label, because aftertreatment and dosing hardware differs between the EPA07, EPA10 and GHG14 builds and a mismatched procedure can send you to the wrong component. For engine coverage and dealer service information, see the Detroit Diesel official website.
Who needs this DEF system circuit low manual
Fleet technicians and independent workshops that service Detroit DD Series engines use this DEF system circuit low reference to confirm the code, its enabling conditions and the correct repair before replacing parts. It is written for the mechanic making the repair decision, not the driver, and pairs with the wiring diagrams and component removal procedures Detroit publishes in Power Service Literature.
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