Detroit SPN 3364 / FMI 2: DEF-quality warning information
The cited Detroit EPA10 reference describes SPN 3364/FMI 2 as a DEF-quality diagnostic condition. The code alone is not a fluid contamination test. Keep the FMI and engine generation with the number when requesting diagnosis.
Application & limits
Detroit bulletin 10 12-15, October 2015, EPA10 SPN 3364/FMI 2. Do not use its response or test limits for another FMI or a later generation. Confirm the current vehicle-specific information.
What the symptom or code tells you
The historical diagnostic includes software and fluid-testing branches. It does not support condemning the fluid or ordering a sensor from the display alone.
Tell the mechanic when the message appeared relative to any refill or repair. That history helps prepare the visit, but it is not proof of contamination, dosing failure or a particular repair.
Information to send
Use details already available from the normal operator position or your records. Do not run a test or approach a hazard to collect them.
- Engine model/serial, truck year/VIN and emissions generation.
- Exact SPN 3364/FMI 2 and the full warning message.
- Other faults, active/inactive status and previous diagnostic records.
- Recent DEF refill or system work and the current location.
What the mechanic assesses
An application-specific assessment determines the current diagnostic path and any required fluid, software or system checks. Do not drain or mix the fluid, replace parts or run a regen as a universal response to this code. The mechanic confirms scope and suitable work conditions first.
Prepare a repair request
Text the machine or vehicle, exact symptom and location. We confirm scope, safe access, parts needs, pricing and availability before a visit.
Serving Langley, Port Kells and the Lower Mainland service area. Readers elsewhere can use the source references and contact a qualified local service provider.
Related service & guides
Sources & applicability
Editorial update: . Public manufacturer and authority references checked on this date. Current vehicle-specific procedures and superseding information must be matched to the actual application before diagnosis or repair.
- Detroit bulletin: SPN 3364/FMI 2
Detroit bulletin 10 12-15, October 2015. EPA10 SPN 3364/FMI 2 reference; other FMI values and generations differ.