2017~2024 Little tidbit of battery info

[wlong01]

If you run the battery down more than likely the rear hatch will no longer open.
System will go into a fail-safe model.
To reset disconnect the battery for 10 minutes, hopefully you will have a battery tender to save your favorites/settings/etc.

Not sure this is mentioned in the manual.

 

[edmaz]

It might help if you explained this a bit more. How much did the battery 'run down' - so much that the vehicle wouldn't start, or less than that? And also do you know why it ran down? Did you see a message or code describing this 'fail-safe' condition, or was it just not opening with repeated attempts? Did you try to recycle the system by manually opening the liftgate?

Although I can understand how the PLU might be programmed to recognize a low voltage condition and shut down liftgate operation, it's puzzling why there wouldn't be a resumption to normal operation once the voltage returned to an acceptable level. So do you know what the recharged voltage at the battery was?

If there actually is a programmed locking by the PLU requiring a hard reset, then it would seem that a recycling of the PLU fuse would accomplish that, without needing to disconnect the battery.

 

[murky]

If you run the battery down more than likely the rear hatch will no longer open.
System will go into a fail-safe model.
To reset disconnect the battery for 10 minutes, hopefully you will have a battery tender to save your favorites/settings/etc.

Not sure this is mentioned in the manual.

Wouldn't a battery tender prevent the reset?

 

[wlong01]

It might help if you explained this a bit more. How much did the battery 'run down' - so much that the vehicle wouldn't start, or less than that? And also do you know why it ran down? Did you see a message or code describing this 'fail-safe' condition, or was it just not opening with repeated attempts? Did you try to recycle the system by manually opening the liftgate?

Although I can understand how the PLU might be programmed to recognize a low voltage condition and shut down liftgate operation, it's puzzling why there wouldn't be a resumption to normal operation once the voltage returned to an acceptable level. So do you know what the recharged voltage at the battery was?

If there actually is a programmed locking by the PLU requiring a hard reset, then it would seem that a recycling of the PLU fuse would accomplish that, without needing to disconnect the battery.

As far as I can tell the battery ran down to zero. Nothing worked, not even the light imbedded in the start button. Doors wouldn't open, nothing. Took about 12 hours to bring it back to a full charge. According to Mazda service when the battery is run down the hatch controller goes into some kind of fail-safe, will not reset until the negative battery terminal is dis-connected.

This is what the Mazda tech told me so I have to take it at face value.

There was no way from the outside to open the liftgate and I didn't want to crawl in and see if there was a manual release inside. It's under warranty and I was taking it in to replace the battery so I let Mazda deal with it.

The battery ran down because my wife left it running and it ran out of gas and I guess a few things were on inside, once the engine quit the accessories drained the battery. Probably the heater fan ran it down pretty quickly.

 

[edmaz]

... According to Mazda service when the battery is run down the hatch controller goes into some kind of fail-safe, will not reset until the negative battery terminal is dis-connected. ...

Thanks for filling in the missing pieces. Yes, I'll just leave it there as well, because I have no interest in testing this out on my vehicle

Just an FYI if you're not already aware, that such a deep drain of the battery probably shortened its life, so you might want to monitor to see how well it holds the charge, especially if it goes a number of days between start ups.

 

[wlong01]

Thanks for filling in the missing pieces. Yes, I'll just leave it there as well, because I have no interest in testing this out on my vehicle

Just an FYI if you're not already aware, that such a deep drain of the battery probably shortened its life, so you might want to monitor to see how well it holds the charge, especially if it goes a number of days between start ups.

I know, that's why I was at dealer today, to replace the battery. We'll be going away soon to some isolated areas and I don't want to take a chance, especially since it took Mazda roadside 8 hrs to get to us when it died.

 

[sm1ke]

There was no way from the outside to open the liftgate and I didn't want to crawl in and see if there was a manual release inside. It's under warranty and I was taking it in to replace the battery so I let Mazda deal with it.

Hi @wlong01, for future reference, there is a manual release. The instructions for accessing the manual release can be found here.

 

[wlong01]

Hi @wlong01, for future reference, there is a manual release. The instructions for accessing the manual release can be found here.

Yes, I know. There was no urgent need to get in the back.
Manual release would not of fixed the problem though.
Since I was going into the dealer for a battery I let them do the reset.
Since they were replacing the battery it probably reset on it's own when they removed the original battery.
So only harm from this whole fiasco was I had to replace the battery early. I usually replace every three years regardless. Such is life.

 

[Ranman57]

Push button start/stop is certainly easier, but doesn't come without some inherent dangers. It's very easy to leave the car running accidently if you're distracted, I did it once in my wife's car and left it running in a grocery parking lot for a 1/2 hour or so.

Here's a sort of scary article on it.

The Danger of Keyless-Ignition Systems

The technology is convenient (if sometimes annoying), but it means drivers need to be more attentive to whether their engines are running.

www.caranddriver.com

 

[joemazdacx5]

That link that sm1ke posted about jumping battery-
why does the negative connector have to be connected to
that #4 position (not on the battery?)
just wondering ..

 

[HyFlyer]

@joemazdacx5 , I don't see the link you're referring to but two reasons I can think of off the top of my head ...

When charging (which is what is happening when you "jump" start also) a battery, flammable hydrogen gas can be produced and escape from the battery's venting system. If you have both jumper cable (or charger) connections at the battery posts there is a possibility of the sparks from connecting/disconnecting the cable igniting those flammable hydrogen gas vapors and causing an explosion. That's bad since your battery contains sulfuric acid and could shower you.

Another reason is many modern vehicle systems have current sensors to determine battery condition so you need to attach the ground cable of your jump or charger to a frame source instead of the battery.

 

[wlong01]

That link that sm1ke posted about jumping battery-
why does the negative connector have to be connected to
that #4 position (not on the battery?)
just wondering ..

Probably to avoid sparks igniting something. When the Mazda roadside guy came he hooked but neg/pos cables directly to the battery and the car started fine.

 

[joemazdacx5]

Oops...He posted a link for the hatch, but further in the manual
it has stuff about the battery...Pic.

Attach negative to point 4 but guess it's to prevent fire...As stated by wlong and hyflyer. Thanks.