Cummins ISM CM870 (2003-06) Fault Code: 143 PID: P100 SPN: 100 FMI: 1/18 Engine Oil Rifle Pressure – Data Valid But Below Normal Operating Range – Moderately Severe Level. Engine oil pressure signal indicates engine oil pressure is below the engine protection warning limit.

The engine oil pressure sensor measures the pressure of the oil in the oil rifle on the left-hand side of the engine block.

Possible causes:

1)Mechanical failures such as lubricating oil pump, lubricating oil high pressure relief valve, loose lubricating oil filter
2)Breakdown or contamination of the lubricating oil
3)Plugged lubricating oil filter.