TL;DR the lock and start button won’t work after replacing the battery, with everything else working just fine.
Have a 2018 QX60 with push button start. Replaced battery after low battery warning on dash came up a few times, but within a few days of 1st notice. Replaced with a new Energizer battery. Fob wasn’t registering or Incorrect Key ID error on dash when got back in so put it next to the start button and pressed unlock a few times until it started working again. Now the fob works to unlock, raise / lower rear door & the alarm and registers to start the door as soon as I get in. However, the door lock and start wont work. Everything still works on my other remote just fine and I’ve taken the key apart again and cleaned it but lock & start still not working. It will also lock with the handle button when I have the fob near so it’s just the lock and start button on one remote that won’t work after replacing the battery with everything else operating as it should.
Have a 2018 QX60 with push button start. Replaced battery after low battery warning on dash came up a few times, but within a few days of 1st notice. Replaced with a new Energizer battery. Fob wasn’t registering or Incorrect Key ID error on dash when got back in so put it next to the start button and pressed unlock a few times until it started working again. Now the fob works to unlock, raise / lower rear door & the alarm and registers to start the door as soon as I get in. However, the door lock and start wont work. Everything still works on my other remote just fine and I’ve taken the key apart again and cleaned it but lock & start still not working. It will also lock with the handle button when I have the fob near so it’s just the lock and start button on one remote that won’t work after replacing the battery with everything else operating as it should.