security system/passlock

I just bought a 1998 blazer. I can not figure out the security system. You have to put the key in the run position for about 3 seconds wait for a beep beep and then start it right away. If try before or too long after the beep beep it will not start. Is this a factory option or after market? Is it a passkey system bypass? The key I have does not have the little resistor I have seen on older GM cars.

That's gotta be aftermerket, I'd be extremely surprised if any manufacturer would force you to switch to the run position and then just give you a short window in which to crank the engine. The factory passkey systems are entirely transparent to the user. So long as you use the correct key you'll never know it's there.

That's gotta be aftermerket, I'd be extremely surprised if any manufacturer would force you to switch to the run position and then just give you a short window in which to crank the engine. The factory passkey systems are entirely transparent to the user. So long as you use the correct key you'll never know it's there.

Thats Kinda what I thought. I guess I just don't get the idea behind this thing.

Do the newer passkeys still have that resistor on the shaft? Or is the transponder in the plastic case?