Oil Low lamp illuminates

[gilloz]

I changed the oil in my daughter's 1999 Pontiac Grand AM SE, 2.4L 4-Cyl. about two days ago. We live in the High Desert of SoCal where the weather is starting to get hot. Her normal oil requirement is 5W-30. She has close to 150K miles on the car. I used, instead, 10W-30 oil. Replaced the oil drain plug and oil filter. I added 4 Qts. plus .4 Qts. for the filter. After 1 hour I looked at the dip stick and the oil was right on the Full mark. Yet, my daughter reports that if she makes sudden or quick stops, the add oil lamp illuminates and sounds off a Chime. What would cause this if the oil marker indicates Full? This lamp will not come ON if her stops are slow or normal. Any ideas?
I failed to add that this Oil Low lamp only momentarily blinks at these sudden stops. It goes OFF when stopped or when the car is in motion.

 

[Zimgxp]

Could be a bad switch, or the oil sloshing in the pan on hard stops.

 

[gilloz]

That was it. The oil pressure sensor was not only bad, it was leaking oil also. I finally ended up taking the car to a local mechanic. Within 15 minutes he found the problem. Makes it easier to have a hydraulic lift. Thanks Zimgxp for your response. Hit the nail on the head. Note: I made in error calling it an Low Oil light. It was actually the Oil Pressure Light.