There are cliffs at the end.
Originally, my 2004 350z with about ~70k miles came with a cheap ebay key. 3 months after purchase my car would intermittently not start. It would crank, my battery seemed to have enough voltage, everything checked up except for the anti theft system that cut off my fuel pump. I went to a nissan dealership and they determined that they key was the culprit, so i got a brand new nissan certified key and went on my way.
7 months later the problem returned, i went to a different nissan dealership (back home) and they checked my nats, said it didn't have a problem, so they wanted to replace the IMMU ring in the ignition cylinder. If that didnt work then they wanted to continue on and replace the BCM, and if that didn't work then unfortunately the ECM afterso.
The codes the brought up were as follows:
P1615 (Difference of key)
U1000 (CAN COMM CIRCUIT)
I didnt have enough money at the time and the problem seemed to go away for about two months. When the problem came back, i went to a third nissan dealership and they tried testing for codes and ONLY the difference of key code came up.
They then suggested i replace my key AGAIN since maybe the key the first nissan dealership gave me might be faulty
I'm now frustrated and confused as what to do. I know its a long read but how am i supposed to know whats wrong if a dealership cant even figure it out? I don't want to spend money where not needed.
-Intermittent False start (cranks, wont start)
-Got a new key (had an old ebay key before), worked fine for 7 months
-problem came back, one nissan dealership told me to replace an IMMU ring, --another told me to replace my key AGAIN
google wouldn't help much on the whole diagnosis aspect