1C0001 is a fault stored in your BMW's memory (an ISTA fault code, not a standard OBD-II P-code).
What it means: Engine oil-pressure control — implausible reading (pressure fluctuations). The engine computer (DME) sees a mismatch between the oil pressure it commands and what the sensor reports. Often shows up as a "Drivetrain Malfunction" message or the iDrive oil-level check getting stuck/failing, and can appear as an intermittent "shadow" code. Common causes: a failing electronic oil pump or pressure-control valve (notably on high-performance engines like the S58), a faulty oil-pressure sensor, or oil-change issues (wrong oil viscosity, a clogged/damaged filter, debris). It can also be triggered briefly if the car was run with the wheels spinning on a lift. Get an ISTA scan and an oil-pressure check at a specialist — don't ignore a genuine low-pressure warning.
