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SPN 4360 — SCR Catalyst Inlet Gas Temperature, Aftertreatment 1

Safe to driveEnough to reach the yard

J1939 code SPN 4360. 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.

Dongfeng

FMI 2Excessive temperature difference between SCR inlet and outlet. Scan tool code: P0426. Effect: Fan and warm-up control may misbehave.
FMI 3Short circuit to power or open circuit of the SCR inlet temperature sensor. Scan tool code: P042D. Effect: OBD limits torque immediately.
FMI 4Short circuit to ground of the SCR inlet temperature sensor. Scan tool code: P042C. Effect: OBD limits torque immediately.
FMI 13Temperature sensor connectors swapped. Effect: Torque limited, MIL on, power may drop to 60%.
FMI 15Engine torque limitation caused by too high SCR catalyst temperature

SITRAK

FMI 0Dynamic plausibility check of the SCR upstream temperature sensor: upper threshold exceeded. Scan tool code: P0426. Effect: Fan and warm-up control may misbehave.
FMI 1Dynamic plausibility check of the SCR upstream temperature sensor: lower threshold exceeded. Scan tool code: P0426. Effect: Fan and warm-up control may misbehave.
FMI 2Static plausibility check of the SCR upstream temperature sensor. Scan tool code: P0426. Effect: Fan and warm-up control may misbehave.
FMI 3SCR upstream temperature sensor voltage too high. Scan tool code: P042D. Effect: OBD limits torque immediately.
FMI 4SCR upstream temperature sensor voltage too low. Scan tool code: P042C. Effect: OBD limits torque immediately.
FMI 5Open load: the catalyst upstream temperature message is missing. Effect: Fan and warm-up control may misbehave.
FMI 9SCR catalyst intake gas temperature signal failed the SAE check. Effect: Fan and warm-up control may misbehave.
FMI 12Implausible SCR catalyst upstream temperature. Scan tool code: P20ED. Effect: Fan and warm-up control may misbehave.
FMI 13Incorrect data length of the A1SCREGT1 CAN frame. Effect: Torque limited, MIL on, power may drop to 60%.
FMI 16SCR upstream temperature physical value above the upper limit. Scan tool code: P20ED. Effect: Fan and warm-up control may misbehave.
FMI 18SCR upstream temperature physical value below the lower limit. Scan tool code: P20ED. Effect: Fan and warm-up control may misbehave.
FMI 19Incorrect data length of the outlet NOx sensor CAN frame
FMI 20Dynamic plausibility of the SCR upstream temperature: minimum error. Scan tool code: P242A. Effect: Fan and warm-up control may misbehave.
FMI 21Dynamic plausibility of the SCR upstream temperature: maximum error. Scan tool code: P242A. Effect: Fan and warm-up control may misbehave.

What FMI means in J1939

SPN 4360 FMI 04360/0 · 4360.0data above normal range (most severe level)
SPN 4360 FMI 14360/1 · 4360.1data below normal range (most severe level)
SPN 4360 FMI 24360/2 · 4360.2data erratic or intermittent
SPN 4360 FMI 34360/3 · 4360.3voltage above normal or shorted high
SPN 4360 FMI 44360/4 · 4360.4voltage below normal or shorted to ground
SPN 4360 FMI 54360/5 · 4360.5current below normal or open circuit
SPN 4360 FMI 94360/9 · 4360.9abnormal update rate
SPN 4360 FMI 124360/12 · 4360.12faulty device or component
SPN 4360 FMI 134360/13 · 4360.13calibration out of range
SPN 4360 FMI 154360/15 · 4360.15above normal — low severity
SPN 4360 FMI 164360/16 · 4360.16above normal — moderate severity
SPN 4360 FMI 184360/18 · 4360.18below normal — moderate severity
SPN 4360 FMI 194360/19 · 4360.19error in received network data
SPN 4360 FMI 204360/20 · 4360.20data drifted high
SPN 4360 FMI 214360/21 · 4360.21data drifted low

Can I keep driving

Safe to drive. Below — how much time you have and what happens if you keep going.

What happens if you keep driving

Time you have: Enough to reach the yard

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.

What to check on the spot

Fill the AdBlue tank. If it’s already full, the problem is dosing or reductant quality — you need a scanner.

Nearby: AdBlue / exhaust

Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.