Key fob or battery problem? 2015 Touring 2WD

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Heretic

Member
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2015 CX-5 Touring FWD
I left my car at an airport parking lot for 72 hours, and upon my return, the key fob would not unlock the car. I had to pull out the manual key to get in. The car starts, and then my keyfob starts working again. Driving around, many short stops, no issues.

Then it happened again a couple of nights ago - I left my car outside overnight and in the morning, had to repeat the procedure above.

Is my battery slowly dying? The car starts with no effort, but the starter doesn't turn over with the same...vigor, for lack of a better word. Or is the problem with my key fob battery?


Thanks for any feedback!
 
Could be both.
The OEM batteries are reported to last 3 years or a little more. The fob batteries maybe a couple of years or less.
 
Seabright said:
Could be both.
The OEM batteries are reported to last 3 years or a little more. The fob batteries maybe a couple of years or less.
Click to expand...

Thanks Seabright! I just put a fresh CR2032 in the fob, the litlle red LED does light up a lot brighter than before - We'll see!

The CR2032 does fit even though it's slightly thicker than the recommended CR 2025 - hopefuly it'll last a little longer too.
 
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Key fob or battery problem? 2015 Touring 2WD

Heretic said:
Thanks Seabright! I just put a fresh CR2032 in the fob, the litlle red LED does light up a lot brighter than before - We'll see!

The CR2032 does fit even though it's slightly thicker than the recommended CR 2025 - hopefuly it'll last a little longer too.
Click to expand...
I wouldn't use CR2032 for CR2025 application in our key fob. Having a good name brand CR2025 would last longer than a cheap no-name CR2032. But watch out those counterfeit name brand cell batteries they're everywhere! (boom06)
 
Heretic said:
The CR2032 does fit even though it's slightly thicker than the recommended CR 2025
Click to expand...
I'm pretty sure the numbers refer to sizes, ie a 2025 is 20 millimetres by 2.5mm thick, and a 2032 would be 3.2mm thick.
 
Right - I'm not sure how the brand factors in, I'm just talking thickness difference between 2 batteries of the same brand.

Anyway, I'll find out tomorrow. I'm away from my car for 48 hours, and need to make sure my AAA membership is current in case I need a jump! ;)
 
Heretic said:
Right - I'm not sure how the brand factors in, I'm just talking thickness difference between 2 batteries of the same brand.

Anyway, I'll find out tomorrow. I'm away from my car for 48 hours, and need to make sure my AAA membership is current in case I need a jump! ;)
Click to expand...

Brand factors in by way of quality and consistency. A Panasonic battery is going to last longer and be more consistent than a battery made by Bubba's Battery Company. The Panasonic may cost a little more but it's well worth it.
 
Conrad 16.5 said:
Brand factors in by way of quality and consistency. A Panasonic battery is going to last longer and be more consistent than a battery made by Bubba's Battery Company. The Panasonic may cost a little more but it's well worth it.
Click to expand...

Bubba's Battery Company only makes shrimp.
 
Heretic said:
I left my car at an airport parking lot for 72 hours, and upon my return, the key fob would not unlock the car. I had to pull out the manual key to get in. The car starts, and then my keyfob starts working again. Driving around, many short stops, no issues.

Then it happened again a couple of nights ago - I left my car outside overnight and in the morning, had to repeat the procedure above.

Is my battery slowly dying? The car starts with no effort, but the starter doesn't turn over with the same...vigor, for lack of a better word. Or is the problem with my key fob battery?


Thanks for any feedback!
Click to expand...

Sounds like you just need to replace the battery in your key fob. I had to replace mine about a year ago. It wore out, had to use the key to get in. Started a couple times, then even that didn't work anymore and had to push the fob against the button to start it (it has that little RFID chip).

By that point, finally figured out how to open the fob to replace the battery :)
 
Kaps said:
Bubba's Battery Company only makes shrimp.
Click to expand...

The company branched out into batteries when the shrimp became overfished. The battery business isn't doing all that well either, it seems that their batteries smell funny...

F6DERZOIDUQMGPW.MEDIUM.jpg
 
Conrad 16.5 said:
Brand factors in by way of quality and consistency. A Panasonic battery is going to last longer and be more consistent than a battery made by Bubba's Battery Company. The Panasonic may cost a little more but it's well worth it.
Click to expand...

Agreed - but that's just a different conversation than 2025 vs. 2032. In theory, a Bubba CR2032 should last longer than a Bubba CR2025 due to its bigger size. In practice, the Panasonic CR2032 I just put in my key fob could be a dud and last half as long. ;)
 
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Mazda Roadside Assistance

Heretic said:
⋯ I'm away from my car for 48 hours, and need to make sure my AAA membership is current in case I need a jump! ;)
Click to expand...
You do have free Mazda Roadside Assistance to cover that ⋯ ;)
 
Heretic said:
Agreed - but that's just a different conversation than 2025 vs. 2032. In theory, a Bubba CR2032 should last longer than a Bubba CR2025 due to its bigger size. In practice, the Panasonic CR2032 I just put in my key fob could be a dud and last half as long. ;)
Click to expand...

That's true! I'd trust the Panasonic CR2032 over the Bubba CR2032 though.
 
Verdict is in: Key fob opened doors on first try. Thanks everyone for the good advice and good cheer!
 
I bet walk away to lock has something to do with not so great battery life in the fob. The fob is always transmitting to let the car know you're leaving it.

Sent from my XT1585 using Tapatalk
 
~18 mos of ownership and I just replaced the battery in the fob I use day in/out.
 
7eregrine said:
I bet walk away to lock has something to do with not so great battery life in the fob. The fob is always transmitting to let the car know you're leaving it.

Sent from my XT1585 using Tapatalk
Click to expand...

I don't believe the fob is constantly transmitting, the fob battery wouldn't last long at all if this were true. I'd bet that these types of systems all work about the same way.

The system on my motorcycle (Kawasaki) uses a 'keyless' fob to activate the ignition. The fob only transmits when the key knob on the bike is pressed. When the key knob is pressed the bike sends out a signal. The fob 'sees' this signal and then sends out a response to the bike. If the response is correct the bike is then allowed to start.

I'm sure that the Mazda system works in a similar manor.
 
You highlighted the wrong part of my post.
"I bet walk away to lock has something to do with not so great battery life in the fob"

How does the car know you are leaving it? I shut the car off, and walk away and the doors lock. There could be some type of passive transmission going on.
 
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