How do I unlock my engine to start it again after adding oil after the low oil pressure light was on?

Yep, I must agree with tennisshoes 100%. Sorry to be the messengers on this Christina but it is very likely your engine is flat-lined - dead -seized from lack of oil, the life blood of an engine. An '03 Silverado probably has a 4.3L or 5.3L and either one you can get a used engine for about $1,000 or a rebuilt for about $2,000 to $2500. Be careful with used engines, you really don't know what you are getting. There are good, well maintained used engines available but it's a roll of the dice. Good Luck.

I would love to get "Best answer" by giving you some good news however all I can do is join the consensuses, How long did you drive the truck after the light came on .. and did it stop by itself:? If it seized then it;s a boat anchor .. A silver lining may be if you hit something on the road that damaged the oil pan and all the oil flooded out... it may be a stretch but perhaps insurance will cover it ;; if you don't volunteer that you drove it for more then a few seconds

GOOD point Tom. Damage from road debris is damage under comprehensive coverage. Christina , give Tom the 'best answer' please. It locked up from no oil, the engine is toast and there is no 'unlock' button

My truck had the right amount of oil, it never ran hot or showed low oil pressure. I drove it Sunday and on Monday I tried to go somewhere it would not start. Wal-Mart changed my oil a month ago and now I have this problem

Umm no dumbasses you can easily unsieze a motor without rebuild everyone on here thinks they are mechanics this will be my 8th motor that I've insisted with a breaker bar spend 2000 dude more than likely works for gm

Anything over an 01 gm will kill itself before it locks up what are we driving cars without cpms or back in the 60s

On a 2008 Silverado with a 4.3 how do you unlock the motor. It was low on oil but it just shut off ideing and won’t turn off at all. It’s like everything is seized