Dead Key Fob

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Well that explains why none of the watch stores I went had a 3025 battery and they all had the 2025.
Maybe my battery was old but it appears to have been used up at six months. I still have to put in a new one to confirm that's the problem. Tomorrow.
Sorry about giving out wrong battery type. Somehow I either made a type-o or my mind was blanked-out while I was typing, the old-age symptom.

Nevertheless the Panasonic CR2025 battery in our key fobs should last 2 years after the CX-5 came out of factory including the time of shipping and sitting in the dealer’s lot. And there’re signs when your battery has become weaker, such as a low-battery warning message displayed in instrument cluster, or the tiny red LED indicator on key fob is really dim when you press the buttons. IMO either you have a defective battery, or less likely a defective key fob.
 
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2019 Mazda CX-5 GT Reserve
I had the same issue with my son's Mazda3. Even the spare was dead & had never been used. Just replaced them both. A year sounds about right. My current CX-5 had been sitting on the dealer's lot for at least 4 months prior to my taking delivery. I'm curious as it's coming up on the one year mark since it first showed up at the dealer. I always got at least 3+ years on my previous VW's.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
I had the same issue with my son's Mazda3. Even the spare was dead & had never been used. Just replaced them both. A year sounds about right. My current CX-5 had been sitting on the dealer's lot for at least 4 months prior to my taking delivery. I'm curious as it's coming up on the one year mark since it first showed up at the dealer. I always got at least 3+ years on my previous VW's.
The CR2025 battery on remote key fob of my 1998 Honda CR-V usually lasts more than 8 years, it’s on the 3rd battery right now. The battery on remote key fob of my 2000 BMW 528i has never been replaced. Of course these remote key fobs in older non-push-botton-start system are different and the electricity is used only when you press the key fob button, whereas key fobs for push-botton-start system consume electricity constantly for periodical polling. Hence the battery can last a lot longer than push-button-start key fobs. On my BMW key fob it has a build-in rechargeable battery and it gets recharged by magnetic power whenever the key is in the ignition.
 

mazdadude

ZOOOOOOOOOM ZOOOOOOOOOM
:
'16.5 Mazda CX-5 Touring
I like to look at the LED indicator on the fob as a visual clue for battery life.
I have gotten usually 2 years out of the fob batteries with the 13-16 CX-5's.
However, our normal usage utilizes the auto lock function on the car, and we do not have a trunk release button on our remote, so the buttons on the fob are hardly ever used.
 
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2018 CX-5 GT PP
Can anyone confirm that the CR2032 fits?

Confirmed. Just changed mine since I have lots of 2032 because it's used by many devices.

Car was occasionally giving me a low battery alert. Original battery is probably only 18 months old but I leave the fob in the car at home. After the swap, the old battery tests at 2.97v so plenty of life. We'll see if alerts go away.
 
I bought a SUV(SIG) that lists for around $38,000. Then, I spend time debating whether to pay $7.00 for 2 batteries for my FOB and change them every 6 months or wait until the red light dims or I have to hold it up to the ignition to start. Sadly, my wife doesn't know about holding to up to the ignition. Am I crazy or cheap or just a typical CX-5 owner?
 

Avoidin Deer

Zoom Zoom, baby
Contributor
:
Central Virginia
:
2019 CX-5 Reserve
Confirmed. Just changed mine since I have lots of 2032 because it's used by many devices.

Car was occasionally giving me a low battery alert. Original battery is probably only 18 months old but I leave the fob in the car at home. After the swap, the old battery tests at 2.97v so plenty of life. We'll see if alerts go away.
THe manual says that the fob goes dormant if left in the car for a period of time, and you have to "wake it up."

This is from Pg 3-8 of the 2019 CX-5 manual:
Key Suspend Function
If a key is left in the vehicle, the functions of the key left in the vehicle are temporarily suspended to prevent theft of the vehicle. To restore the functions, press the unlock button on the functions-suspended key in the vehicle.

If the 2018 this way? Do you have to wake up the fob, or can you just get in your car and push the Start button?

One would think that leaving the key in the car might actually save fob battery life, since the functons are suspended.
 
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2018 CX-5 GT PP
If the 2018 this way? Do you have to wake up the fob, or can you just get in your car and push the Start button?

Just push Start. That suspend bug would be annoying. If someone breaks into our garage to steal the car, they will have a very bad day.
 

Pitter

Pitter
Contributor
:
2020 CX-5 Signature Azul Metalico
Replaced the batter and key fob works fine so that obviously was the issue. But I do wonder why the original only lasted six months. I wonder if I am doing something that discharges it.
 

Avoidin Deer

Zoom Zoom, baby
Contributor
:
Central Virginia
:
2019 CX-5 Reserve
Replaced the batter and key fob works fine so that obviously was the issue. But I do wonder why the original only lasted six months. I wonder if I am doing something that discharges it.
I'd only worry about it if this battery is also short-lived.
Could just be the state of the original battery.
 
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2014 & 2019 CX-5 Touring(s)
This is why I took the battery out of my second fob before storing. Now I just have to hope there's no cycling code that would stop it working when/if I need it :)
 

Avoidin Deer

Zoom Zoom, baby
Contributor
:
Central Virginia
:
2019 CX-5 Reserve
This thread caused me to set my second fob up with an extra set of keys and start using it. If one of them is gonna take a poop, let's have it happen under warranty.
 
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CX5 GT
Probably all know it, but one can still start the car with low or very degraded fob battery, just have to use the key to unlock the door and touch the fob to the start button and push with it.
 

Pitter

Pitter
Contributor
:
2020 CX-5 Signature Azul Metalico
Battery was indeed my problem as expected. But I remain surprised that it only lasted six months after both the dealer and many folks here say it's good for at least a year and in some accounts much more. So that leads me to wonder what I am doing wrong regarding the key fob.
 

Avoidin Deer

Zoom Zoom, baby
Contributor
:
Central Virginia
:
2019 CX-5 Reserve
Battery was indeed my problem as expected. But I remain surprised that it only lasted six months after both the dealer and many folks here say it's good for at least a year and in some accounts much more. So that leads me to wonder what I am doing wrong regarding the key fob.
There's not much you can do to cause battery drain other than a continuous pull on it, like having a button on it constantly pressed as you drive. I've never pushed any of the buttons while in motion, so don't know if there would be any "You can't do that" beeps or alarms.

I've only used one fob for the past year and just started using the second one a few days ago. Both batteries seem to be strong, but I hardly ever use the remote functions...I use Walk-Away-Locking and the buttons on the door & hatch handles to unlock.

So unless you let your gato play with it...
 

Pitter

Pitter
Contributor
:
2020 CX-5 Signature Azul Metalico
The battery that came with the car and which gave out early was a Panasonic made in Indonesia. I saw no warning on the dash. The symptom was that I began to have to press multiple times to get it to activate, the last time about six times at which point I went to the other key fob. The suggestion of a bad original battery seems to make the most sense. As to my gato playing with it's a gata and one time while I was bathing she knocked one of my hearing aids to the floor and played with it like a hock puck wham, ka-pow and that of course was the end of it.
 
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