Safe to driveDrivable, but watch it yourself
SPN 4033 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, MAN and Renault Trucks, and what the second half of the code (FMI) means.
InternationalKnorr-Bremse EBSMANRenault Trucks
| FMI 5 | Sleeper Remote - Start/Stop Enable Command — Sleeper Control Enable Relay Under Current or Open Circuit |
| FMI 6 | Sleeper Remote - Start/Stop Enable Command — Sleeper Control Enable Relay Over Current |
| FMI 3 | Central control unit, EEPROM unknown value. Not identified |
| FMI 3 | Central control unit EEPROM memory ISR - Not identified |
| FMI 4 | No messages from the Astronic unit or from the VECU. Repair: Check the Astronic or VECU unit for faults; if an Astronic unit is fitted, check the CAN bus communication with the Astronic unit, check the CAN bus communication with the VECU, the resistance between the two wires is 60 ohms (pins 22, 49). |
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.