Safe to driveEnough to reach the yard
J1939 code SPN 102. Below — how the fault is worded at the factory by DAF, Dongfeng, Foton, Isuzu, KAMAZ, MAZ, Renault Trucks, SITRAK and YaMZ, and what the second half of the code (FMI) means in the standard.
DAFDongfengFotonIsuzuKAMAZMAZRenault TrucksSITRAKYaMZ
| FMI 2 | Relative boost pressure F649 implausible pressure (extended period) |
| FMI 3 | Relative boost pressure F649 voltage too high at ECU pin A19 (extended period) |
| FMI 4 | Relative boost pressure F649 voltage too low at ECU pin A19 (extended period) |
| FMI 16 | Relative boost pressure F649 pressure too high |
| FMI 2 | Incorrect intake manifold pressure signal |
| FMI 3 | Intake pressure sensor short circuit to ground |
| FMI 4 | Short circuit to power or open circuit of the intake pressure sensor |
| FMI 18 | Actual air-fuel ratio below the limit. Scan tool code: P023D. Effect: Torque limited, black smoke. |
| FMI 0 | Boost pressure above allowed limit |
| FMI 16 | Insufficient turbocharger efficiency. Scan tool code: P023D. Effect: Torque limited, black smoke. |
| FMI 18 | Boost pressure below allowed limit. Scan tool code: P023D. Effect: Torque limited, black smoke. |
| FMI 3 | Boost pressure sensor fault (low voltage fault) (P0237) |
| FMI 4 | Boost pressure sensor fault (high voltage fault) (P0238) |
| FMI 0 | Boost pressure sensor: physical range limit. K-line code on KamAZ-5490: MR2 11820. |
| FMI 1 | Boost pressure sensor: physical range limit. K-line code on KamAZ-5490: MR2 11818. |
| FMI 2 | Boost pressure sensor. K-line code on KamAZ-5490: MR2 11417. |
| FMI 3 | Boost pressure sensor. K-line code on KamAZ-5490: MR2 11415. |
| FMI 4 | Boost pressure sensor. K-line code on KamAZ-5490: MR2 11416. |
| FMI 7 | Boost pressure, turbocharger. K-line code on KamAZ-5490: MR2 11876. |
| FMI 12 | Boost pressure sensor |
| FMI 13 | Boost pressure, turbocharger. K-line code on KamAZ-5490: MR2 11873. |
| FMI 2 | Boost pressure sensor circuit fault - Plausibility error. Blink code: 2-3-1. Power will be reduced. Repair: Check the boost pressure sensor and its wiring. |
| FMI 3 | Boost pressure sensor circuit fault - Voltage above allowed. Blink code: 2-3-1. Power will be reduced. Repair: Check the boost pressure sensor and its wiring. |
| FMI 4 | Boost pressure sensor circuit fault - Voltage below allowed. Blink code: 2-3-1. Power will be reduced. Repair: Check the boost pressure sensor and its wiring. |
| FMI 12 | Boost pressure sensor circuit fault - CAN bus signal implausible. Blink code: 2-3-1. Power will be reduced. Repair: Check the boost pressure sensor and its wiring. |
| FMI 3 | Boost pressure sensor — short to positive (5 V or battery voltage). Repair: Check the sensor and the wiring (J 1/27, J 1/35, J 1/36). Check the sensor and the engine wiring (A 3, A 19, A 34). Check the sensors (X1B/11). Run the diagnostic check of the tachograph unit. Check the programming. Switch the ignition off, switch it on again and repeat the test. If the fault persists, replace the control unit. |
| FMI 4 | Boost pressure sensor — open circuit or short to ground. Repair: Check the sensor and the wiring (J 1/27, J 1/35, J 1/36). Check the sensor and the engine wiring (A 3, A 19, A 34). |
| FMI 15 | Boost pressure above normal. Repair: Check the sensor and the engine wiring (A 3, A 19, A 34). |
| FMI 16 | Boost pressure sensor, supply voltage too high. Repair: Check the sensor, the EECU and the engine wiring (A 3, A 19, A 34). |
| FMI 18 | Boost pressure sensor, supply voltage too low. Repair: Check the sensor, the EECU and the engine wiring (A 3, A 19, A 34). |
| FMI 0 | Excessive turbocharger boost pressure |
| FMI 1 | Turbocharger boost build-up failure, class 1 |
| FMI 2 | TIP sensor activation fault |
| FMI 3 | High voltage on TIP sensor |
| FMI 4 | Low voltage on TIP sensor |
| FMI 16 | Air pressure upstream of the intake valve above the upper limit. Scan tool code: P023D. Effect: Torque limited, black smoke. |
| FMI 18 | Air pressure upstream of the intake valve below the lower limit. Scan tool code: P023D. Effect: Torque limited, black smoke. |
| FMI 2 | Boost pressure sensor circuit fault (Plausibility error). Blink code: 2-3-1. Power will be reduced. Repair: Check the boost pressure sensor and its wiring. |
| FMI 3 | Boost pressure sensor circuit fault (Voltage above allowable limit). Blink code: 2-3-1. Power will be reduced. Repair: Check the boost pressure sensor and its wiring. |
| FMI 4 | Boost pressure sensor circuit fault (Voltage below allowable limit). Blink code: 2-3-1. Power will be reduced. Repair: Check the boost pressure sensor and its wiring. |
| FMI 12 | Boost pressure sensor circuit fault (CAN bus signal implausible). Blink code: 2-3-1. Power will be reduced. Repair: Check the boost pressure sensor and its wiring. |
Safe to drive. Below — how much time you have and what happens if you keep going.
Boost is not reaching its target: turbo, intercooler or intake. The engine compensates with mixture and runs hotter than usual.
You will lose pull, burn more fuel and add overheating on long climbs. If you hear a whine or a whistle from the turbo, stop — the wheel is breaking up.
This is an electrical fault: an open, a short or a bad contact in the sensor circuit. The value it measures is most likely fine. You can drive. But until the circuit is repaired this system runs blind and cannot warn you about a real failure.
That said, the manufacturer flags this code as critical — if in doubt, it is safer to stop and check on the spot.
Inspect the air filter and charge-air hoses: leaks and cracks produce exactly these codes.
If the value really did go out of range, rather than a sensor circuit being broken, these normally light up after it:
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.