Safe to driveDrivable, but watch it yourself
SPN 520743 is a manufacturer number outside the standard J1939 table: different makes can put different things under it. Below — how it is worded by International, and what the second half of the code (FMI) means.
| FMI 5 | Transmission PTO Engagement Actuator Command — TEM PTO Engagement Relay Under Current Or Open Circuit |
| FMI 6 | Transmission PTO Engagement Actuator Command — TEM PTO Engagement Relay Overcurrent |
| SPN 520743 FMI 5520743/5 · 520743.5 | current below normal or open circuit |
| SPN 520743 FMI 6520743/6 · 520743.6 | current above normal or grounded circuit |
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.