Safe to driveTo the nearest safe stop
J1939 code SPN 3513. Below — how the fault is worded at the factory by DAF, Dongfeng and SITRAK, and what the second half of the code (FMI) means in the standard.
| FMI 3 | 5V sensor supply voltage too high at ECU pin B26 |
| FMI 4 | 5V sensor supply voltage too low at ECU pin B26 |
| FMI 3 | Sensor No. 5 supply voltage too high. Scan tool code: P1602. |
| FMI 4 | Sensor No. 5 supply voltage too low. Scan tool code: P1603. |
| FMI 3 | Internal sensor supply voltage too high. Scan tool code: P1602. |
| FMI 4 | Internal sensor supply voltage too low. Scan tool code: P1603. |
| SPN 3513 FMI 33513/3 · 3513.3 | voltage above normal or shorted high |
| SPN 3513 FMI 43513/4 · 3513.4 | voltage below normal or shorted to ground |
Safe to drive. Below — how much time you have and what happens if you keep going.
The electrical system is not holding voltage. While the engine runs the alternator carries it; shut it off and you may not restart.
Next the lights go, then modules start dropping out and false codes appear all over the truck. Get to somewhere with help without shutting the engine down.
Check the battery terminals and earth strap — corrosion and loose clamps throw false codes all over the truck. Running voltage should be 27–29 V.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.