Safe to driveDrivable, but watch it yourself
SPN 523612 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 and YaMZ, and what the second half of the code (FMI) means.
| FMI 3 | CJ940 module supply voltage above/below limit |
| FMI 4 | CJ940 module supply voltage above/below limit |
| FMI 3 | ECU CJ940 module supply error - Internal supply voltage above normal. Blink code: 2-6-3. Repair: Replace the ECU. |
| FMI 4 | ECU CJ940 module supply error - Internal supply voltage below normal. Blink code: 2-6-3. Repair: Replace the ECU. |
| FMI 3 | ECU CJ940 module power supply fault (Internal supply voltage above normal). Blink code: 2-6-3. Repair: Replace the ECU. |
| FMI 4 | ECU CJ940 module power supply fault (Internal supply voltage below normal). Blink code: 2-6-3. Repair: Replace the ECU. |
| SPN 523612 FMI 3523612/3 · 523612.3 | voltage above normal or shorted high |
| SPN 523612 FMI 4523612/4 · 523612.4 | voltage below normal or shorted to ground |
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.