Infinity i35 2002 follow up post to yesterday

[Edzo]

My 2002 infinity i35 has two issues I am concerned with. I brought the car to AutoZone and they were kind enough to diagnose the car for free. The first item was code P1611, definition anti theft system (nats) failure. The second code is P0605, faulty ECM. Regarding security the security light stays lit and the car cranks but won't start while this light is lit. The light has shut off from time to time and the car starts and runs just fine.
Regarding the ECU I am guessing it is the Air bag or AB harness. The vehicle air bag light is flashing. In an effort to self diagnose I discovered it flashes once long then a pause then rapidly flashes eight times. The info. I have indicates this flashing is code for the passenger side air bag/AB Harness. Any suggestions for cure, reference material or steps to fix are appreciated. Thx Edzo

[Edzo]

After a couple of hours on line looking for an answer, I think I found one concerning the security light. I took the cars original ignition key and inserted the key, turn the key on, waited five seconds and turn off then repeat the process three more times. The car security light went out and the car started. Did both keys. Hopefully that problem is solved. Will post again if it fails later. I think having the original keys the car was able to recognize them with the procedure followed. Do not think a new key would be programmed this way. That would have been my next step. I found a locksmith a couple of miles from my house who has successfully programmed infinity keys for half the dealer fee.

[Edzo]

Just a side note. I think my wife tried to start my 02 i35 with our 04 i35 keys and set off the security issue. Is that possible? I have to label her keys. The older we get the more confused we are.

[5star4real]

Hey Edzo,

I believe that is what may have occured.

I too own a i35-2002 and a i35-2004 (first and last years they were made )

I have on occasion tried to use my 2004 key in the 2002 i35 and after putting it in the ignition and then realizing wrong, I try and use my 2002 key and the system just cranks and cranks and does not start with a solid security light.... solution is as you've discovered is to simply remove and insert the proper key in the ignition and turn to acc on my case and wait 5-10seconds...then the car turns right over...and its nothing wrong the the car as I can replicate this issue at will even on the other car using the wrong key

cheers

[Edzo]

Well the security light is back on and the car wouldn't start. Finally started and I'm not sure why it started. I was looking on line at other sights. Many people had replaced alternators, batteries etc. without permanent success. One person posted the ignition switch is usually the real culprit. The usual suspect is found to be a brittle wire connected to the ignition. Any one out there familiar with this theory? If so, how difficult is this project and what do I have to worry about?