Safe to driveDrivable, but watch it yourself
SPN 520232 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 255 | Service signal: cylinder output test |
| FMI 20 | Individual cylinder performance test in progress - Test in progress, misfire monitoring disabled. Blink code: 5-2-3. |
| FMI 11 | ECU internal monitoring reported a fault, function monitoring level (MoF). Scan tool code: P101C. |
| FMI 4 | Voltage at the LCM input is below 7 V, or the ignition key was in the start position for more than 60 seconds. Ignition switch contact set damaged, fuse F17 blown, wire between the LCM and the fuse box shorted to ground, or low battery voltage. |
| FMI 20 | Individual cylinder performance test in progress (Test running, misfire monitoring disabled). Blink code: 5-2-3. |
| SPN 520232 FMI 4520232/4 · 520232.4 | voltage below normal or shorted to ground |
| SPN 520232 FMI 11520232/11 · 520232.11 | root cause not known |
| SPN 520232 FMI 20520232/20 · 520232.20 | data drifted high |
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.