I've experienced more frequently lately that the key is in the cup holder and it says the key is not detected. Also, it happened several times the past 2 weeks that the car would not start and said I had to press on the brake and place the key fob by the start button. Why is that? Is it anything for concern that I should take the car in?

 

Sounds like a dead battery in the key fob.

 

The key fob battery was replaced by the service dept as part of the service.

 

Doesn't necessarily mean the battery is good.

 

Have you tried using the other Key FOB?

 

Doubtful.. but perhaps

 

Deffinitely fob battery.try Panasonic,Murata

 

These things are so easy to install I wouldn't bother with dealer on this one. Plus you never know if they've screwed up the retention tabs for the button shaped battery. If they're broken you might not get good contact. Dealer may have old or cheap or stale batteries plus maybe didn't put in a CR2032 but a weaker CR 2025. Both will fit but the latter is much weaker battery.

https://www.ic-components.com/blog/U...025%20Overview

See my post #54 on how to install both key card and fob batteries:

https://www.clublexus.com/forums/nx-...uestion-4.html