Idiot Oil Light

Dipstick is not correct for the car giving you an incorrect reading?

Do an oil change, add the correct oil amount plus the one for the filter. Then che k the level on the dipstick.

Another could be a leak in the pickup just under the full level, when you hit the breaks oil moves forward allowing the leak to suck air.

My 273 does this when I got close to 2 qt low, (I know it should never get that low, that's another story)

I agree in changing the sender my old sender would show low pressure when full and ideling, replaced it and no more issue