I'm not sure if the W210 works the same way, but in the W124s there is a circuit in the instrument cluster that delays the oil low lamp until it gets a positive signal from the sensor for around 45 sec or so. This prevents the light from coming on and off during cornering, braking, or accelerating. When the circuit is busted, the light comes on whenever the sensor registers a low oil level condition, which generally results in intermittant warnings even when the oil level is fine.