Safe to driveEnough to reach the yard
J1939 code SPN 4363. Below — how the fault is worded at the factory by Dongfeng and SITRAK, and what the second half of the code (FMI) means in the standard.
| FMI 3 | Short circuit to power or open circuit of the SCR outlet temperature sensor. Scan tool code: P0428. Effect: Fan and warm-up control may misbehave. |
| FMI 4 | Short circuit to ground of the SCR outlet temperature sensor. Scan tool code: P0427. Effect: Fan and warm-up control may misbehave. |
| FMI 15 | High catalyst temperature |
| FMI 0 | SCR catalyst downstream temperature sensor plausibility, maximum threshold. Scan tool code: P042A. Effect: Fan and warm-up control may misbehave. |
| FMI 1 | SCR catalyst downstream temperature sensor plausibility, minimum threshold. Scan tool code: P042A. Effect: Fan and warm-up control may misbehave. |
| FMI 2 | Implausible SCR catalyst downstream temperature. Scan tool code: P20EC. Effect: Fan and warm-up control may misbehave. |
| FMI 3 | SCR downstream temperature sensor voltage too high. Scan tool code: P0428. Effect: Fan and warm-up control may misbehave. |
| FMI 4 | SCR downstream temperature sensor voltage too low. Scan tool code: P0427. Effect: Fan and warm-up control may misbehave. |
| FMI 9 | SCR catalyst outlet gas temperature signal failed the SAE check. Effect: Fan and warm-up control may misbehave. |
| FMI 12 | Static plausibility check of the catalyst downstream temperature sensor failed. Scan tool code: P246E. Effect: Fan and warm-up control may misbehave. |
| FMI 14 | Timeout of the A1SCREGT1 CAN frame. Effect: Torque limited, MIL on, power may drop to 60%. |
| FMI 19 | Incorrect data length of the outlet NOx sensor CAN frame |
| FMI 22 | Static plausibility check of the catalyst downstream temperature sensor failed. Scan tool code: P042A. Effect: Fan and warm-up control may misbehave. |
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.
That said, the manufacturer flags this code as critical — if in doubt, it is safer to stop and check on the spot.
Fill the AdBlue tank. If it’s already full, the problem is dosing or reductant quality — you need a scanner.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.