Hey Neilo
The factory Remote Receiver boxes are fine.
Its the crappy remotes themselves that have really weak signals. (basically dirty gets under the button but they kinda sealed so you soak in wd40 overnight but I dont think it works well)
20180225_115005.jpg
Now basically he is doing an extra step that is cancelling the other remotes. Do not do step 6.
If I was you and myself have been through this. Buy the following remote (works with factory reciever. no installation required) and the signal is amazing.
I can remote lock up to 50 metres away.
https://www.ebay.com.au/itm/NISSAN-P...AAAOSw-09aNYFo