I have a 06 coupe and cannot figure out what is wrong with her, it started out with the horn going off went to take horn fuse out and it sparked right before took it out , but before that when I would try to crank it it would click so we changed out starter, fuel pump,mass air flow sensor, new battery, main fuse box still would not crank red lite on dash stayed on so I took it to Nissan they reprogrammed the ecm and theft crank and ran three different times I went to pick it up and it died, hasn’t cranked since they said I need a new ipdm which I got, they also said I need a engine room harness which is discontinued but my mechanic friend redid the wires and ipdm so I had it taken to three different shops they said it was the ecm well I had my ecm tested and it works great no shorts no problems so still won’t crank when u put a hot battery in her all the dash lights come on bright and nice but as soon as u turn the key over the fan comes on and all the dash lights go off and nothing and my red light on dash is still solid. We tried to jump the starter and nothing car won’t even turn over. Can someone please help me she’s been down a year now

 

Red light on the dash means the BCM doesn't recognize the RFID chip in your key and the NATS (security sent from BCM) is preventing the ECM from opening injectors/coil packs.

Usually this is just because the RFID chip in the key died, they only last like 15 years or so.

Fan running with the ignition ON but the engine not running is usually indicative of a failing IPDM, normally what happens is they get wet either because someone didn't put the cover on correctly or the battery box drain is clogged and fills up with water and submerges the IPDM, or the cowl drains are clogged and water is pouring on top of the IPDM.

Sometimes you can fix by disassembling it and putting it in a bag of rice like you would do to dry out a cell phone, usually it requires a new IPDM. They are VERY chassis/package specific though so make sure it has the exact same part number as the one equipped on your vehicle or it will do the fan on / horn on even though it's technically not water contaminated.

 

I could be wrong but I'm fairly sure the RFID chip that's molded into the tiny plastic end of our physical keys is of the "passive" variety, as in it has no power source of its own. My understanding is that the "NATS antenna amplifier" located in our backup key slot (near the driver's left knee) - or which used to be in the ring around the ignition and driver's door key slots - actually generates the power to make that chip respond. So I thought these embedded chips had no expiration date...?

The iKey and previous generation remote fobs are certainly "active" units but luckily we can replace those batteries.

 

That's correct its a passive RFID but they only last 10-15 years in automotive use. Either temp changes cold/hot expansion/contraction causes the antenna to peel away, or the internal memory fails. My guess is it's probably the internal memory failing that causes most keys to die, any powerful magnetic field (like storing your keys on top of your microwave) is going to essentially overload the little memory chip over time. They're definitely not permanent.

I'm sure there's a lot of variables due to manufacturing quality but the Nissan keys are fairly notorious for randomly dying.

 

Wow, I learn something new every day - and usually from cleric670.
We own his and hers 2013 Gs so that makes me think I should pull the batteries out of the fobs and test the backup systems just to see if they still work. It would be a drag to discover that failure right when you needed it...

 

Yeah and this is a big reason why I'm such a strong proponent of having a second set of keys for anything that uses RFID interlocks. It's just a matter of time before that key will fail and it helps a ton with the troubleshooting. If the second key will work then you had one key die, if both keys won't work then there's some other issue.

The G35 is also slightly prone to losing the RFID code in the BCM, if both keys fail you can usually just reprogram the BCM to accept them again. I still haven't figured out exactly why they do this but there's usually a dozen people per year that have to get their car reprogrammed here on this site.

 

Just like early generation "Personal Computers" used to occasionally forget the date and reset to 1980, the processors that run our cars are fairly rudimentary. The BCM might even have a CMOS battery in it to keep the BIOS firmware alive - I don't know. After years of heat / cold / vibration mounted on the firewall I'm not surprised these boxes occasionally flake out and forget everything they're supposed to remember.