Cummins Fault Code
Free · no signupCummins 119 (SPN 135 FMI 4)
Low oil pressure alarm; 0 PSI on gauge; Engine may shutdown automatically.
System
Not specified
Symptom
Low oil pressure alarm; 0 PSI on gauge; Engine may shutdown automatically.
Diagnosis & fix steps
Oil Pressure Voltage Low.
LOGIC: Signal < 0.5V (Short to Ground). The ECM expects a base voltage even at 0 PSI. A drop below 0.5V indicates the signal is touching ground.
ACTION: 1. Check oil level/dipstick (Safety First).
2. Unplug sensor; if code becomes FMI 3, wiring is good, sensor is dead.
3. Check for 5V ref on Pin A.
FIX: Replace Oil Pressure Sensor or repair signal wire rub-point.
Red Seal field insights
If you are stuck in a dangerous spot and need to move the machine, unplugging the sensor sometimes defaults the ECM to a "safe" pressure value, allowing you to limp it out of the way.
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