Safe to driveDrivable, but watch it yourself
SPN 4063 is a manufacturer number outside the standard J1939 table: different makes can put different things under it. Below — how it is worded by Knorr-Bremse EBS and MAN, and what the second half of the code (FMI) means.
| FMI 4 | Speed sensor, CAN data channel. No signal |
| FMI 10 | Yaw angle sensor, CAN data channel. Open |
| FMI 4 | Speed sensor CAN communication - No signal |
| FMI 10 | Yaw angle sensor CAN communication - Open |
| SPN 4063 FMI 44063/4 · 4063.4 | voltage below normal or shorted to ground |
| SPN 4063 FMI 104063/10 · 4063.10 | abnormal rate of change |
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.