I believe it's just a simple float switch, in which case the float is bad.

They either sink or the case cracks and leaks oil -- not much else to fail.

however, at that mark on the dipstick, it's possible you are getting a low enough oil level on sharp turn for the light to come on for a couple seconds.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!