Security light/ Pass key problem

This problem happens off and on alot in the past month. Some times my car doesn't start and I have to wait the 3 mine for the security light to go off. Other times the security light comes on while I'm driving. I have tried both my keys and cleaned them both and I'm still having the problem. Some times I have to turn the key 20+ times before it will start.

Since I have tried both keys I'm assuming it is a problem with the lock cylinder not reading the keys. Is this expensive to get fixed? Can I fix it on my own? Anyone else have this problem?

it is fixable on your own. I got stranded when my lock cylinder went for good. SO i was forced to get it fixed at a chevy dealer. Total cost was 350 with parts & labor.

Measure the resistance of the pellet in the key. Then wire the correct resistors into the wire underneath the kick panel in the dash. You can go to shoebox's website to find the correct wire.

Or you can do what I did, program it out. I have disabled VATS.

http://shbox.com/1/4th_gen_tech2.html#pass_key
check that
then read the disable section no programming required