Safe to driveDrivable, but watch it yourself
SPN 520201 is a manufacturer number outside the standard J1939 table: different makes can put different things under it. Below — how it is worded by KAMAZ, MAZ, SITRAK, Volvo and YaMZ, and what the second half of the code (FMI) means.
| FMI 3 | BET air temperature sensor |
| FMI 4 | BET air temperature sensor |
| FMI 3 | Ambient air temperature sensor fault - Voltage above allowed. Blink code: 2-3-5. Repair: Check the ambient air temperature sensor and its wiring. |
| FMI 4 | Ambient air temperature sensor fault - Voltage below allowed. Blink code: 2-3-5. Repair: Check the ambient air temperature sensor and its wiring. |
| FMI 19 | No communication with the CY320 chip inside the ECU. Scan tool code: P0607. |
| FMI 3 | LCM output voltage to the lamps is equal to or higher than battery voltage. Wires between the LCM and the lamps shorted to a higher voltage, or lamp failure. |
| FMI 4 | LCM output voltage to the lamps is below 2 V. Wiring between the LCM and the lamps shorted to ground. |
| FMI 5 | LCM output current to the lamps is below 0.1 A. Open supply wire between the LCM and the lamps, open wire between the lamps and the ground point, or lamp failure. |
| FMI 6 | LCM output current to the lamps is above 5.8 A. Wire shorted to ground between the LCM and the lamps. Possibly several additional lamps are connected, or a higher-wattage lamp is installed. |
| FMI 3 | Ambient air temperature sensor fault (Voltage above allowable limit). Blink code: 2-3-5. Repair: Check the ambient air temperature sensor and its wiring. |
| FMI 4 | Ambient air temperature sensor fault (Voltage below allowable limit). Blink code: 2-3-5. Repair: Check the ambient air temperature sensor and its wiring. |
Safe to drive. Below — how much time you have and what happens if you keep going.
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.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.