Safe to driveDrivable, but watch it yourself
SPN 4038 is a manufacturer number outside the standard J1939 table: different makes can put different things under it. Below — how it is worded by International, Knorr-Bremse EBS and MAN, and what the second half of the code (FMI) means.
InternationalKnorr-Bremse EBSMAN
| FMI 5 | Snow Plow Forward Lighting Relay 2 — Right Plow Light Relay Under Current Or Open Circuit |
| FMI 6 | Snow Plow Forward Lighting Relay 2 — Right Plow Light Relay Circuit Short To Ground |
| FMI 8 | Central control unit, EEPROM checksum error ASR. Wrong signal |
| FMI 8 | Central control unit EEPROM ASR configuration - Wrong signal |
| SPN 4038 FMI 54038/5 · 4038.5 | current below normal or open circuit |
| SPN 4038 FMI 64038/6 · 4038.6 | current above normal or grounded circuit |
| SPN 4038 FMI 84038/8 · 4038.8 | abnormal frequency or pulse width |
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.