Safe to driveDrivable, but watch it yourself
SPN 4023 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 Renault Trucks, and what the second half of the code (FMI) means.
| FMI 2 | Lift Gate Power Control Switch — Lift Gate Switch Error |
| FMI 4 | No messages from the ABS/EBS unit. Repair: Check the ABS/EBS unit for faults, check the CAN bus communication with the EBS unit, the resistance between the two wires (22, 49) is 60 ohms. |
| SPN 4023 FMI 24023/2 · 4023.2 | data erratic or intermittent |
| SPN 4023 FMI 44023/4 · 4023.4 | voltage below normal or shorted to ground |
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.