Hi from Lynchburg, Va. I have very similar if not exact same problem as Muhoms1. I had my X for three days and it wouldn't start. Installed a new battery, terminal ends and had starter checked. security light blinks every second suggesting security system is disengaged but key won't even turn starter over. Towed to local mechanic who spent full day troubleshooting and ended up getting solution from local Nissan dealership to use key in driver door lock with key turned to lock and unlock for specific time periods and it unlocked. Mechanic said if I had repeat problem to call and he would walk me through unlocking security lock out. I paid for an hour diagnostics and new relay and all was well for another month or so. last week it happened again at home so I called and Mech. was on vacation. waited for his return and he tried to remember key moves but to no avail. he didn't want more $$ he just forgot. we tried many variations but to no avail. He suggested I tow truck to Nissan and pay for diagnostic to see why repeat of lock out. My question is this, if a simple key in the door lock and turning left/right for x amount of time is all that is needed to override lockout why is it not in the manual or more common knowledge on the net? Does this sound familiar to anyone? Have you had similar issues to release security lockout with a key without a keyfob. I have no keyfob, previous owner lost all. Question: can I remove the security fuse block from under the hood next to the battery and just not use the security system which causes so much trouble?? Mystified in Va. Doug.