Detroit fault code 3216 FMI 4 DTCs is the TruckFaultCodes.com diagnostic sheet for the SCR Inlet NOx Sensor Circuit Failed Low condition on Detroit DD-series engines. This 1 page reference lists the fault identification, monitored conditions where shown, and the step-by-step troubleshooting the technician follows in the shop.
Official document details
| Brand | Detroit |
|---|---|
| Model coverage | Detroit DD Series (EPA 2007-Current) |
| System / Group | DD Series (EPA 2007-Current) / DTCs |
| Publication no. | Not printed; TruckFaultCodes.com reference |
| Year / Revision | 2017 |
| Pages | 1 |
| File size | 0.3 MB |
| Format | |
| Language | English |
Document table of contents
- Fault code identification (SPN 3216 / FMI 4)
- Description and monitored parameters
- Enabling conditions and dash lamps
- Troubleshooting steps
- Sensor replacement reference
3216 FMI 4 DTCs troubleshooting steps
The sheet monitors SCR Inlet NOx Sensor. Typical duration is 2 seconds, the dash lamps are MIL and CEL, and the engine reaction is none.
The procedure starts by reading the DTC occurrence counter. When the counter is five or less the fault is cleared and the vehicle released; when it is higher the SCR inlet NOx sensor is replaced using the EPA10 outlet NOx sensor removal procedure in Power Service Literature. Verification is a one-minute engine idle.
Applicable truck models
This sheet applies to Detroit DD-series diesel engines (the DD13, DD15 and DD16 family) built under the EPA 2007-Current emissions platform, in its EPA10 calibration. Engine and emissions specifications should always be confirmed against the vehicle build; full engine information is published on the Detroit Diesel official site.
Who needs this 3216 FMI 4 DTCs manual
Mechanics working EPA10 Detroit DD-series aftertreatment faults use this sheet to confirm whether an inlet NOx sensor circuit reading low should be cleared or the sensor replaced. It is a quick bench reference rather than a full workshop manual, so the named removal steps still route back to Power Service Literature and, where escalation is needed, to the Detroit Customer Support Center.
The full PDF is available in the DiagTechPro manuals library; a free account is required to download it.
Related manuals library
