I was driving normally and the no key light popped up. (Every time I started my car it pops up, and always had problems locking/unlocking my car. I have to put the key directly next to the door to unlock it) then it happened again and the car just shut off then it wouldn't turn on, after trying and trying, I got it to turn on and the service engine light came on. I drove a little more than all the lights shut off[headlights, dash, center console] then the engine turned off so when I got it back on again the lights stayed off and said there was no key but I was able to get it back to home. The car is a 08 g37, and I just put a new battery in the key fob. Any ideas are appreciated.

 

I'd be wondering about your car's battery and/or charging system. These cars can get some pretty wacko symptoms when the voltage gets low.

 

Get a new battery for your key!

 

 

Do you have both keys that came with the car?

If so, try swapping them out to see if it does it with either key...

 

Maybe the battery you got was a dud.

That's all the problem should be, the other option is resetting the ECU. Unplug the battery overnight and then plug it back in, in the morning. See what happens.

Only other idea is that the fob could be damaged

 

I have an odd issue with my key fob as well, its not as severe, the range is no longer as far as it use to be. I thought it was the battery too so i swapped it but still the same :/ hope it doesn't get worse, "knocks on wood"...

btw https://www.myg37.com/forums/d-i-y-i...isconnect.html takes some practice to get it