Safe to driveEnough to reach the yard
J1939 code SPN 132. Below — how the fault is worded at the factory by KAMAZ, MAZ, Renault Trucks, SITRAK, YaMZ and ZF AS-Tronic, and what the second half of the code (FMI) means in the standard.
KAMAZMAZRenault TrucksSITRAKYaMZZF AS-Tronic
| FMI 3 | Air flow sensor: signal out of range |
| FMI 4 | Air flow sensor: signal out of range |
| FMI 3 | Mass air flow sensor signal out of range - Voltage above allowed. Blink code: 2-3-4. Repair: Check the mass air flow sensor and its wiring. |
| FMI 4 | Mass air flow sensor signal out of range - Voltage below allowed. Blink code: 2-3-4. Repair: Check the mass air flow sensor and its wiring. |
| FMI 0 | Shift sensor initialisation fault. Repair: Switch the ignition off, switch it on again and repeat the test. If the fault persists, replace the control unit. |
| FMI 2 | Air mass flow sensor (HFM) hardware failure. Scan tool code: P0103. Effect: Torque may be limited. |
| FMI 3 | Air mass flow sensor frequency signal above the upper limit. Scan tool code: P0103. Effect: Torque may be limited. |
| FMI 4 | Air mass flow sensor frequency signal below the lower limit. Scan tool code: P0102. Effect: Torque may be limited. |
| FMI 11 | Air mass flow sensor (HFM) supply failure. Scan tool code: P0100. Effect: Torque may be limited. |
| FMI 22 | Air mass flow sensor (HFM) signal short to ground. Scan tool code: P0100. |
| FMI 3 | Mass air flow sensor signal out of allowable range (Voltage above allowable limit). Blink code: 2-3-4. Repair: Check the mass air flow sensor and its wiring. |
| FMI 4 | Mass air flow sensor signal out of allowable range (Voltage below allowable limit). Blink code: 2-3-4. Repair: Check the mass air flow sensor and its wiring. |
ZF AS-Tronic uses its own fault numbering: the number in the table below is an internal ZF code, not a J1939 SPN. It matches the title of this page by digit only and means something different.
| FMI 9 | Self-test fault on the shift sensor (main gearset). |
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.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.