Do not driveMinutes
J1939 code SPN 19. Below — how the fault is worded at the factory by Mercedes-Benz, Renault Trucks and ZF AS-Tronic, and what the second half of the code (FMI) means in the standard.
Mercedes-BenzRenault TrucksZF AS-Tronic
| FMI 2 | J1939 Engine Retarder Selection Signal Missing or not available = SNA (signal not available) |
| FMI 5 | Short to 0 V. Repair: Check the wiring between the control unit and the clutch actuator (X1B/7, X1B/16). Run the diagnostic check of the clutch actuator. If the fault persists, replace the control unit. |
ZF AS-Tronic uses its own fault numbering: the number in the table below is an internal ZF code, not a J1939 SPN. It matches the title of this page by digit only and means something different.
| FMI 5 | Short circuit to ground on valve Y15 output (clutch slow engagement). |
| SPN 19 FMI 219/2 · 19.2 | data erratic or intermittent |
| SPN 19 FMI 519/5 · 19.5 | current below normal or open circuit |
Do not drive. Stop as soon as it’s safe to do so — don’t keep going.
The oil film in the bearings is already breaking down. Every minute under load is metal on metal on the crank journals.
Next comes spun bearings and a full engine rebuild. Shut it down now and coast to the shoulder without revving.
The pressure itself is most likely fine: this is an electrical fault — an open or a short in the sensor circuit, not lost oil. You can drive, but the dash will no longer warn you about a real pressure drop. Until the circuit is repaired, check the level with the dipstick at every stop.
Shut the engine down. Check the oil level with the dipstick and look underneath for leaks. Don’t restart until pressure is back.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.