Safe to driveDrivable, but watch it yourself
SPN 523615 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 2 | Injection pump metering unit (PWM): open circuit / overheating / short circuit |
| FMI 3 | Injection pump metering unit (PWM): open circuit / overheating / short circuit |
| FMI 4 | Injection pump metering unit (PWM): open circuit / overheating / short circuit |
| FMI 5 | Injection pump metering unit (PWM): open circuit / overheating / short circuit |
| FMI 16 | Injection pump metering unit channel ADC |
| FMI 18 | Injection pump metering unit channel ADC |
| FMI 2 | High-pressure pump metering unit PWM driver circuit fault - Overheating. Blink code: 1-3-5. Power will be reduced. Repair: Check the high-pressure pump metering unit and its wiring. |
| FMI 3 | High-pressure pump metering unit PWM driver circuit fault - Short to battery positive. Blink code: 1-3-5. Power will be reduced. Repair: Check the high-pressure pump metering unit and its wiring. |
| FMI 4 | High-pressure pump metering unit PWM driver circuit fault - Short to ground. Blink code: 1-3-5. Power will be reduced. Repair: Check the high-pressure pump metering unit and its wiring. |
| FMI 5 | High-pressure pump metering unit PWM driver circuit fault - Open circuit. Blink code: 1-3-5. Power will be reduced. Repair: Check the high-pressure pump metering unit and its wiring. |
| FMI 16 | High-pressure pump metering unit PWM driver circuit fault - Fuel metering unit PWM signal above the allowed range. Blink code: 1-3-5. Power will be reduced. Repair: Check the high-pressure pump metering unit and its wiring. |
| FMI 18 | High-pressure pump metering unit PWM driver circuit fault - Fuel metering unit PWM signal below the allowed range. Blink code: 1-3-5. Power will be reduced. Repair: Check the high-pressure pump metering unit and its wiring. |
| FMI 2 | High-pressure fuel pump metering unit PWM driver circuit fault (Overheating). Blink code: 1-3-5. Power will be reduced. Repair: Check the high-pressure pump metering unit and its wiring. |
| FMI 3 | High-pressure fuel pump metering unit PWM driver circuit fault (Short to battery positive). Blink code: 1-3-5. Power will be reduced. Repair: Check the high-pressure pump metering unit and its wiring. |
| FMI 4 | High-pressure fuel pump metering unit PWM driver circuit fault (Short to ground). Blink code: 1-3-5. Power will be reduced. Repair: Check the high-pressure pump metering unit and its wiring. |
| FMI 5 | High-pressure fuel pump metering unit PWM driver circuit fault (Open circuit). Blink code: 1-3-5. Power will be reduced. Repair: Check the high-pressure pump metering unit and its wiring. |
| FMI 16 | High-pressure fuel pump metering unit PWM driver circuit fault (PWM signal to metering unit above allowable range). Blink code: 1-3-5. Power will be reduced. Repair: Check the high-pressure pump metering unit and its wiring. |
| FMI 18 | High-pressure fuel pump metering unit PWM driver circuit fault (PWM signal to metering unit below allowable range). Blink code: 1-3-5. Power will be reduced. Repair: Check the high-pressure pump metering unit 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.