i headed out on Christmas eve and when i got to my destination i put the car in park and noticed on the dash that the "key" light popped up. i pushed the ignition button to shut off the car and it would not shut off. i drove home and tried for over an hour to shut the car off. i disconnected the positive to the battery, i pulled the fuse and then several variations to shut off the car.
I am pretty sure that the key is fine as all other functions still work fine with the key. eventually it finally worked and the car shut off. i have not tried it again as i don't want the car to be running until i run out of gas.
does anyone know what the problem is before i start it and take it to the garage.

 

I think you will need to take the car to Infiniti or Nissan to have this checked out as it could be an issue with the BCM. Has it ever gotten wet?

https://www.reddit.com/r/G37/comment...wont_shut_off/

 

not that i am aware of.

 

Did you try pressing AND HOLDING the button, or just a simple press? Holding the button down for 3sec. initiates a emergency shutdown. However...

With respect to the BCM, did you even bother to check if there was water in the passenger-side floorboard? It takes all of 2min. to check.

90% of all electrical issues with these cars can be traced to the BCM getting wet. And, being in a colder climate, if it did get wet and the water froze you might have more issues.

 

i did not press and hold the ignition button as i was afraid of doing harm to the starter. i had no idea of the emergency shut down. I checked for water on the passenger floor but it was dry. i think the
bcm may be the issue. last week my brake lights would not shut off until i unhooked the battery after that they were fine. reading about the BCM they say some weird electronics issues happen, i did not think that this might be related to the shut off, but now it seems possible that they may be related. is this an expensive fix?

 

I see used BCMs on eBay for $100-200.

A new one from a place like IPD is about $500: https://www.infinitipartsdeal.com/oe...ol_module.html

This thread talks about how to access the BCM: https://www.myg37.com/forums/body-in...ls-99-a-5.html

It needs to be married to the ECU, so the dealer will need to program the unit. Last I heard this work was in the $150 range.

 

i thank you very much for the help.

 

you have been very helpful. thank you very much

 

A common misconception. The modern "START" button is nothing like it was 60/70+ years ago when the button actually engaged the starter motor. Nowadays, the button just signals modules to trigger a series of relays. No harm/ no foul. For future reference, and for those reading this:

CAR MUST BE IN ANY GEAR BUT PARK!

Again, if the BCM is the issue, the above may still not work.

@socketz67 pretty much covered all that is involved to replacing the BCM, however, I would still consider taking the car to a reputable Nissan mechanic just to verify the problem. I am strongly against throwing parts at a problem blindly. While the BCM may be suspect, it could also be the Unified Meter Amp, antenna, steering lock (if applicable), etc.

Do you have the ability to check for any trouble codes?

Also, if it were me, I would disconnect the battery and check all of the connections at the BCM. Unplug them, one-by-one, and inspect the pins/ terminals for any signs of water, corrosion, dirt, etc.

 

I am going to take it to my mechanic next Monday as i have the week off. As I am sure that you can tell, i don't know much about engines and at almost 70, too old to learn much. that is why I lean on you guys who know much more than i ever will. i am going to heed your advise and tell my guy what you have mentioned in this thread and hopefully get this fixed. i miss the "G" along with it's 357,000 KM's. this was always my dream car and will try everything to keep it on the road til the end.

 

leak from windshield rust was leaking down onto the BCM causing the issues. it was removed and dried out for a couple of days and seems to be fine now. i still need to seal the windshield to keep the water out, but being extremely cold over the past few weeks has prevented this job from being done. waiting for a warm day to heat up the garage and then seal the windshield.