2010 Mazda Mazda6 - Died and offers clues

turned my car off so I could open a gate , and my car would not start. acted like battery was dead . I tried jumping it and still nothing. horn works , trunk pops. a month ago it started making a hmmmm noise soft sounding. A red light comes on on the push button , instead of a green light.

After market security or remote start?

First thing I would try is push the start button with the key fob. If that works chances are yu need a new battery in the fob.

A failing neutral safety switch is a common reason for fails to crank w/ automatic transmission equipped vehicles. Try starting with the transmission in neutral rather park, or try wiggling the transmission shift lever slightly during attempted cranking. If that does the trick the aforementioned safety switch needs to be adjusted or replaced. If nothing else works a shop can do a couple of voltage measurements at the starter motor to get to the bottom of this. Fails to crank is probably the most common complaint we see here. So the shop will have plenty of experience diagnosing this problem.