99 maxima immobilizer issue, programming didn't help
 

I have a 99 maxima that has the security light in while cranking, this obviously means it needs to be reprogrammed, so I. Had locksmith come and try to reprogram it, it didn't work, I took a known working ecu with me just incase and it didn't work, the chip in the key was tested and it is also known to work, they tried reprogramming it several times, still same result, once they reprogrammed it the light shut off and we cranked it but it kept cranking than turned the ignition off and back on again and the security light is back on,

Anyone deal with this?

To start the car and light to be off you need the chipped key, nats module, antenna under steering wheel and ecu to communicate,anything I'm missing


Should I try changing the nats module first instead of the antenna? The ecu and chip inside the key are known and tested to be in working order

Thanks

Yeah, I'd go NATS module

Is it common for the nats module to go like this? I know 99s are stupid when it comes to the keys and programming but this one has got me

I've ran into the same issue once with my 99 maxima. I was experiencing the same symptoms as you and did everything I could to try and get it fixed myself. Unfortunately, I had it towed to the dealer and they reset the computer for just $120.00 After that, started up again like normal. It's the more expensive route, but saves you a whole lot of headache.

I had this symptom that needed to reprogram my keys a couples of times. But the 3rd time happened recently, the dealer said that the ECM did not take a new code when trying to reprogram. They recommended to replace a whole security system instead of ECM module only. Another security module can cause the same symptom. So, by the end, I had no choice but let the dealer replaced the new ECM, NATS, and antenna that cost me nearly $2000 for this dam old car. Yet, no more Nissan for me.