Nissan Repair: 99 Nissan wont start, neutral safety switch, nissan maxima

Question
I have a '99 Nissan Maxima that won't always start.  When this happens, the engine starts (turns over) and it'll just shut off and I'm not able to get the engine started.  This has happened 3 times in the last 3 weeks and when it happens, I have to tow it into a mechanic (I've been taking it to a Nissan dealership repair shop) and when it arrives it starts right up - no problem.  Each time a security sensor shows there may have been a problem but each time the mechanic can't find a problem - resets the system and sends me on my way.  They did reprogram and give me a new set of keys the 2nd time I had the car towed in - but then it wouldn't start about 4 days later.   Since it starts after being towed, could it be a loose wire somewhere?  Could the security system have a problem, if so, can the security system be disconnected somehow? About two months ago the service engine light can on and they said it was the NOC sensor and mechanics just reset it and I haven't had a problem with that since - hoping that's not tied into this problem.  Any thoughts?  

Answer
MK,

When the car does this try shifting it from park to neutral and contunue attempting to start it.  The neutral safety swtich could be going out.  Now, it could be the body control module that controls the security.  but, my bet is with the neutral safety switch or the starter getting old.  Towing might jar the neutral safety switch or the starter brush that is not making contact.  Since there is no code and the knock sensor is not related to starting I would go with the replacement of the cheapest part and that would be the neutral safety switch first and if that does not correct it then the starter.  With intermittent problems you continue the chase until you can duplicate the problem.