2016 Mazda3 hatch i GT ---- In just 700 miles and one week, I came out to go to an appointment yesterday and the battery was dead as the proverbial door nail. I'm 79 miles from one dealer and 81 from the other so I called AAA. After applying their battery charger, I left it on for awhile and called the closest dealer and took it directly there.

Apparently the light in the hatch was on (I didn't even know it was there) and perhaps had been for several days. The day before the dead battery I had all the doors and hatch open to install Weathertech mats. When I got the car going, I noticed the 'door oper' light on the dash. The hatch door was closed but not tight. If the hatch light is on and the door tightly closed, will the light go out? Or is it only dependent on its switch?

#2 At this point while driving I noticed that the Infotainment screen was black. I assumed this was caused by draining the battery. The dealer updated the software and it works fine now.

I'm still working on all the settings so I haven't read everything in the manual yet. Does anyone have comments on these two issues? Have I missed something or made wrong assumptions about cause/effect?

Ironically, we bought this brand because of vaunted reliability reviews from many knowledgeable places. I'd like to believe them.

 

As of Thursday, the problem has been diagnosed and resolved. Thanks to the excellent service at Savannah's Fairway Mazda! At the second visit and after 3 episodes of dead battery, we determined that the OBD2 Blue Driver code reader was the culprit.

I had used it on my previous vehicle but didn't plug it into this one until the 7th day of ownership. From that day until Thursday (17th day) the reader was slowly draining the battery. I don't have tools to check parasitic drain but the first two times it was two days between start attempts and the third was only 12 hours.

When I finally remembered the device was plugged in, told the Serv Mgr, who agreed that it was probably the problem and told the tech, they had had it an hour. An hour after removing the device the reading returned to normal and I haven't had a problem since (48 hrs) and I've started it numerous times.

Thanks for help from others on the Forum! What I've learned in this newbie process of familiarization: 1) the OBD2 drains the battery, 2) the software on my info screen needed to be updated, 3) when the battery is low, the TPMS warning displays and reports 'malfunction' on the Warning Guidance screen, 4) Mazda advises not to install code readers, 5) Mazda also has not taken a position as to whether they are good or bad -- yet.

Finally, the first time I called Mazda Roadside Assistance, the contracted vendor arrived in 45 minutes. However, the second time, the first vendor backed out of the call at 1 hours so a second vendor was contacted and it took that business 2.5 hours to respond. The first dead battery was handled by my AAA contract and that vendor took 1 hour to arrive. I live a minimum of 20-30 minutes from any of these businesses so I expect to have to wait a bit. BUT, 3.5 hours isn't acceptable!

Questions? I'm always happy to help figure all of this stuff out.

 

I'm guessing you don't lock the vehicle when not in use? ( car wont lock if boot is ajar)

It is extremely important to always lock you car when not in use. Failure to do so will keep the BCM in standby mode, causing excessive draining of the battery.

 

Thanks, grim_reaper. Two more nuggets to know. First, you're right. I've gotten out of the habit of locking the car at home, which is where it sits overnight. Although I didn't know about standby mode, I was beginning to wonder on my own if something like that was going on. I understand the process now and will lock every time. It also occurred to me that the battery capacity isn't equal to the requirements served on it by the designers. I still have a LOT to learn about Mazda design and technology!

 

I also suggest to disengaged the Istop every time, it will save your battery.