There's no need to enter in maintenance mode if you'll be doing the front only. Anyways, here's the link for the maintenance mode if ever you decide to check on the rear brakes.
www.mazda6club.com

DIY: - Rear Brake Maintenance Mode for 2016+ Ebrake
Special Thanks are given to Mazdas247.com. This was written by tomcat1446 helping to interpret a difficult service manual. I did this today using his write-up perfectly. Link: https://www.mazdas247.com/forum/showthread.php?123861563-Maintenance-Mode-for-2016-2017-CX-5-electronic-brakes 2...