Safe to driveEnough to reach the yard
J1939 code SPN 3364. Below — how the fault is worded at the factory by Foton and SITRAK, and what the second half of the code (FMI) means in the standard.
| FMI 9 | SCR system fault. Scan tool code: P207F. Effect: Torque limited, MIL on, power may drop to 60%. |
| FMI 2 | Poor DEF quality: the dosing quantity cannot be corrected after a refill. Scan tool code: P203B. Effect: OBD limits torque immediately. |
| FMI 3 | DEF quality sensor signal above the upper limit. Scan tool code: P206A. Effect: Torque limited, MIL on, power may drop to 60%. |
| FMI 4 | DEF quality sensor signal below the lower limit. Scan tool code: P206A. Effect: Torque limited, MIL on, power may drop to 60%. |
| FMI 5 | DEF quality sensor short to battery or open load. Scan tool code: P206A. Effect: Torque limited, MIL on, power may drop to 60%. |
| FMI 6 | DEF quality sensor short to ground. Scan tool code: P206A. Effect: Torque limited, MIL on, power may drop to 60%. |
| FMI 7 | DEF quality sensor signal not available. Scan tool code: P206A. Effect: Torque limited, MIL on, power may drop to 60%. |
| FMI 8 | Absolute DEF quality error, for example sensor drift. Scan tool code: P207F. Effect: Torque limited, MIL on, power may drop to 60%. |
| FMI 9 | Effective DEF quality error, for example the wrong fluid was filled in. Scan tool code: P207F. Effect: Torque limited, MIL on, power may drop to 60%. |
| FMI 10 | The quality sensor cannot determine the DEF quality. Scan tool code: P206A. Effect: Torque may be limited. |
| FMI 27 | DEF quality sensor reported an invalid failure mode identifier. Scan tool code: P206A. Effect: Torque limited, MIL on, power may drop to 60%. |
| FMI 29 | DEF quality sensor signal stuck in range. Scan tool code: P206A. Effect: Torque limited, MIL on, power may drop to 60%. |
Safe to drive. Below — how much time you have and what happens if you keep going.
Urea dosing is interrupted and the ECU is counting. First the lamp, then a torque cut, then a forced crawl speed — the stages come in by engine hours, not all at once.
The truck will not die mid-highway, but the window shrinks with every running hour. Plan the repair now, not when the power is gone: an emulator or "deleting AdBlue" does not remove the problem, the codes keep stacking.
Fill the AdBlue tank. If it’s already full, the problem is dosing or reductant quality — you need a scanner.
This code is often not the fault itself but a knock-on. If any of these is in the same readout, start with it:
These normally light up after this code:
They are not fixed separately — they go out together with this one. The list is deliberately short: only the links the reference is sure about.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.