Do not driveMinutes
J1939 code SPN 1071. Below — how the fault is worded at the factory by KAMAZ, MAZ, SITRAK and YaMZ, and what the second half of the code (FMI) means in the standard.
| FMI 2 | Fan drive (PWM control): short circuit / open circuit / overheating |
| FMI 3 | Fan drive: short circuit |
| FMI 4 | Fan drive: short circuit |
| FMI 12 | Fan drive (PWM control): short circuit / open circuit / overheating |
| FMI 2 | Fan drive driver circuit fault - Overheating. Blink code: 3-1-2. Repair: Check the fan drive and its wiring. |
| FMI 3 | Fan drive 2 driver circuit fault - Short to battery positive. Blink code: 3-1-2. Repair: Check the fan drive and its wiring. |
| FMI 4 | Fan drive 2 driver circuit fault - Short to ground. Blink code: 3-1-2. Repair: Check the fan drive and its wiring. |
| FMI 12 | Fan drive driver circuit fault - Open circuit. Blink code: 3-1-2. Repair: Check the fan drive and its wiring. |
| FMI 2 | Over-temperature of the fan 1 powerstage. Scan tool code: P0480. Effect: The engine may overheat or use more fuel. |
| FMI 2 | Fan drive control driver circuit fault (Overheating). Blink code: 3-1-2. Repair: Check the fan drive and its wiring. |
| FMI 3 | Fan drive control driver circuit 2 fault (Short to battery positive). Blink code: 3-1-2. Repair: Check the fan drive and its wiring. |
| FMI 4 | Fan drive control driver circuit 2 fault (Short to ground). Blink code: 3-1-2. Repair: Check the fan drive and its wiring. |
| FMI 12 | Fan drive control driver circuit fault (Open circuit). Blink code: 3-1-2. Repair: Check the fan drive and its wiring. |
Do not drive. Stop as soon as it’s safe to do so — don’t keep going.
The engine is already past its temperature limit. An aluminium head goes fast: first the geometry warps, then the gasket burns through.
Next comes a blown head gasket, a damaged head and, at worst, a cracked block. Shut it down and let it cool — never open the expansion tank cap while hot.
This is an electrical fault: the sensor or its wiring is lying, not the cooling system. The temperature gauge is unreliable now and the fan may not kick in on time. Watch the coolant level and keep the engine off load on long climbs.
Let the engine cool — never open the expansion tank cap while hot. Then check the level and the hoses.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.