My 1999 wont't crank when ignition turned security light flashes continuously. also checked
battery and jumped solenoid on starter car turns over and runs momentarily. Also gets fuel when key turned to on position. Does this sound like a pass key issue I tried both original keys with the same result. Could it be the contacts on the ignition switch ? Or is there another quick check I can do before doing the by pass thing??
Any feed back would be great ??
Thanks alot Newbie

Check both of your battery cables and clean both ends.

Battery cable ends clean and car turns over great when jumped at starter but wont crank with key

With the security light flashing constantly this appears to be a VATs issue. This is most likely caused by the resistor in your key going bad. Try another key or spare if you have one, if not we can walk you through how to bypass the system if necessary.

If it'* a VATs problem, here is how to bypass it.

https://www.gmforum.com/t279119/

Do u have power to all your windows/ digital climate control? if u have no power at all to that i had the same problem the grounds coming off the negitive post of the battery are grounded behind the battery on the fender check them see if they are loose if they are loose tightin them up and try to start it. just throwin it out there because mine where all loose and it wasnt groundin the ecu to tell the car to fire. took me about a hour to realize my grounds where loose coming off my battery. Well hope this was helpful