Hello, I've been doing a lot of research on this issue but haven't been able to narrow down the issue so I'm hoping for some ideas/suggestions on what terms to search with, or if someone can provide some direct insight into the problem I'm experiencing. This is for an 06 5at base sedan (I think, that's what the VIN came back with).

I'm having an issue with the intelligent key system (I think that's what its called?), even though I don't have an intelligent key. The problem is that the car would intermittently crank without starting and then it would start just fine at other times. Using BL-150, I've been able to figure out that sometimes the key warning lamp will light up as solid red with the key in the on position, and this is when the engine will crank without starting. If I take the key out and back in and try several times to put the ignition to "on", the lamp will not light up any more and the engine will fire up at the first crank. This happens with both sets of keys.

Now here's the thing that I don't know if it is related: I bought a switch key case and transferred everything over. Everything works great and I have no issues with the remote functions. The transponder chips transferred over easily and are held securely.

This problem is intermittent and I can't seem to find a pattern or replicate what might cause the red lamp to illuminate. Could the new switch key cases be causing problems with the transponder chip? Or is this a problem with the intelligent key system, assuming that I have one? Any ideas or suggestions on how to narrow this down further other than taking the ignition apart to test it via the FSM?

 

Can anyone provide some guidance/insight/help???

 

A few questions... So you don't have an intelligent key? As in, you need to press a button on the fob to unlock the car - you don't have small buttons on the door handles you can press to open up - and you put the physical key into the ignition switch to turn it?

What's "BL-150"?

Did you have your original key shape cut into the switchkey case's key? Because you still need a chip which is embedded in the plastic part of the original Infiniti key... The red light on the dash means the car is having trouble finding either your I-Key (if you have it) or the physical key's embedded chip - which should be sensed when you put the key into the ignition switch.

Your service manuals are here:
http://www.nicoclub.com/FSM/G35/Sedan/2006_G35_Sedan/
If you want to read up on the system it's in "bl.pdf" (body, lock and security system)

 

Correct, I don't have the intelligent key system, but the service manual incorporates that into the NATS system it seems. Took me a few days to decipher it.

That's "Body, locks and security system", page 150. had to really pour over it and once I got past the intelligent key system test, I was able to see that it's the same for NATS regardless of whether you have the intelligent key system or not.

Yes, I already have the transponders over in the new cases. No issue there other than 1 part, see below.

Thank you, that was "BL-150" I was referring to.

So I am pleased to say that this mystery is solved. It appears it was a combination of 2 things: the transponder chips for both keys had come loose (what are the odds?!) and voltage required for proximity of detecting transponders. The transponders were not rattling around, but instead sliding up and down a groove that was on the inside of the case. This allowed for the transponder chips to make intermittent contact with the NATS system.

I tested this for 2-3 hours and the proximity sensor varies depending on output voltage, much to my surprise. This is not set from constant voltage but instead is set by the voltage initially fired into the system. That voltage can vary until it becomes constant battery voltage. So depending on how far back the transponder chip is (4-5 inches with key out) and how much voltage is initially fired across the system before becoming constant, I would get mixed results and could not replicate the issue. Securing the chip to within 2-3 inches or less makes the initial voltage irrelevant and will be detected every time.

So what was allowing the transponder to slide around in the grove? It appears that a small plastic tab that helps to hold the key in place had become soft and did not keep the transponder chip as snug as it was originally so the transponder would slowly slide up and down the full case of the switch key. I pried the tab the opposite direction to help hold the chip in place and applied superglue. So far, no issues.

 

Hey nice going! At least I was on the right track. It makes sense that the physical key's transponder chip needs to be very close to, basically IN the ignition switch. No reason to make the scanner that looks for the chip any more powerful than it needs to be. I don't understand what you mean about the output voltage varying, maybe as the system scans? At any rate, glad you figured it out and fixed the issue.

 

I think the initial voltage that fires across the system is the residual power left on the ECM for a fraction of a second before it becomes constant battery voltage when the key is turned to on. I had assumed that with constant battery voltage, the distance to read the chip would remain the same and much to my surprise, that was not the case. That's what I was referring to.

I'm glad too. The fact that it was unpredictable, had no pattern, and could not be replicated in an attempt to rule in/out potential issues drove me nuts!