Replacement Key Fob for 2020 CX-5?

ddingle

Member
:
2020 CX5 Sig
I bought my CX5 slightly used and it was missing one key fob. Now the one I have intermittently stops working. Replaced the battery, but it still goes dead until I pull the battery and then put it back in. At least that is what it seems like is happening. I know they have to be programmed, but wondering is anyone has had a locksmith or the like program a replacement fob? I haven't checked the dealer for pricing, but I suspect around $300. There are plenty of lower cost options, for sale on line, but would still need programming. Looking for any input to help get one and get it programmed for the least amount of money. Thanks in advance.
 
Try to look inside the battery space and maybe give it a good clean with isopropyl alcohol and see if you can raise those tiny battery contacts a bit. Maybe the battery doesn't make a good contact in there.
 
Thanks, Just today I cleaned the contacts and gave them a little bend upwards to improve the contact. Still not sure why it goes dead at this point and with temps in the -20 area I am looking to avoid getting locked out. Should have a second fob anyway. The broker I bought the car from is checking his connections as well.
 
Thanks, Just today I cleaned the contacts and gave them a little bend upwards to improve the contact. Still not sure why it goes dead at this point and with temps in the -20 area I am looking to avoid getting locked out. Should have a second fob anyway. The broker I bought the car from is checking his connections as well.
Did you buy new batteries or use them from your drawer?

Double-check your manual to make sure what battery you need for your year and model.

Some people including people I've known try to shove the CR-2025 into their keyfobs which fit but don't have enough power. The CR-2032 is way more powerful and what is sometimes needed for the keyfob. Again check your manual. my manual had CR-2025 but the keys supplied by dealer had CR-2032 in them and work fine. I've replaced them once already with new CR-2032. Also, make sure your batteries are not old and expired.

Supposedly there is a dealer mode too which you may need to disable the dealer mode so your keyfob works properly.

Lastly try online for key-fobs.
I've even gotten $20 aftermarket keyfobs for ford's that work great and used Nissan key-fobs that just needed reprogrammed for cheap.
 
Last edited:
I don't have any advice for a second fob but switching to a 2032 battery made fob issues go away for my 2019.
 
The newer squarish fob of my 2022 model uses a 2032.
Not sure about the 2021 model.
The fob of my '17 uses a 2025 (thinner one).
(First two numbers = diameter. Last two numbers = thickness)

I had the problem OP described once.
I bend the bottom metal contact upward a bit, and it worked for me.
For sure, I tested the button battery first by a multimeter to make sure it was good.
 
The newer squarish fob of my 2022 model uses a 2032.
Not sure about the 2021 model.
The fob of my '17 uses a 2025 (thinner one).
(First two numbers = diameter. Last two numbers = thickness)

I had the problem OP described once.
I bend the bottom metal contact upward a bit, and it worked for me.
For sure, I tested the button battery first by a multimeter to make sure it was good.
Instead of bending the metal prongs, the thicker 2032 probably inadvertently solves the metal contact problem by filling the void and not allowing the battery to shift in the case. The thinner 2025 maybe was shifting away from the prongs where the 2032 is thick enough to keep it in place. Perhaps that is why my used 2018 from the dealer had 2032 in the keyfob instead of 2025... Just a thought. For whatever reason the 2032 just works better, thicker and more power.
 
I cleaned the contacts, along with bending the contact prongs a little and although the 2025 that I had in the fob was new I replaced it with a 2032. Will try it and see if the problem reoccurs. Here's the quote on new fob from local Mazda dealer :
"Parts quoted the FOB as $203.46 plus tax and the Emergency key as $48.80 plus tax
There is also a KEY programming charge of $170 plus tax and shop supplies."
 
I cleaned the contacts, along with bending the contact prongs a little and although the 2025 that I had in the fob was new I replaced it with a 2032. Will try it and see if the problem reoccurs. Here's the quote on new fob from local Mazda dealer :
"Parts quoted the FOB as $203.46 plus tax and the Emergency key as $48.80 plus tax
There is also a KEY programming charge of $170 plus tax and shop supplies."
Surprisingly the key-fobs don't end up at the junkyard. The car owners(and or insurance companies) usually keep them and maybe sell them on internet. Either get a used keyfob off eBay and pay local locksmith to reprogram(dealership is expensive) or try the website www.keylessentryremotefob.com which we were gonna use for remotes for another non-Mazda vehicle. The aftermarket remotes were really cheap under $100 for the keyfob including the slot key. we got rid of car and no longer needed the extra remotes so haven't tried the site yet and can't comment on the product quality.
 
3 years ago I ordered a 3rd key fob for my 2018 from OEM Car Key Mall for $53.10. I had it programmed at a local locksmith, I think that was $80.
 
I lost a fob once.
My wife and I took a walk around neighborhood.
When we came back, the queen said she lost the key w/ fob attached to it.
Spent hundreds to replace it.

To OP:
If you think adding a 2nd fob is expensive (I know it is), if you should lose your remaining one, it gets 2X more expensive (up to $1000) because you would need to replace the ECU also.
Once both keys are lost, the ECU has to be replaced.
 
⋯ If you think adding a 2nd fob is expensive (I know it is), if you should lose your remaining one, it gets 2X more expensive (up to $1000) because you would need to replace the ECU also.
Once both keys are lost, the ECU has to be replaced.
This can not be true if you lost both key fobs. You should be able to get a set of new key fobs based on your VIN from your Mazda dealer after the verification of car ownership. More expensive and time consuming for sure, but no need for ECU replacement.
 
I cleaned the contacts, along with bending the contact prongs a little and although the 2025 that I had in the fob was new I replaced it with a 2032. Will try it and see if the problem reoccurs. Here's the quote on new fob from local Mazda dealer :
"Parts quoted the FOB as $203.46 plus tax and the Emergency key as $48.80 plus tax
There is also a KEY programming charge of $170 plus tax and shop supplies."
You may have found the solution to your problem! 2020 MY and later use CR2032. This newer key fob has tiny buttons on the side vs older MY that have larger buttons on the front and use CR2025. You can retrieve the emergency key by removing the cover (there is a release pin you can push with your finger nail) and you can start the engine by putting the fob near the start push button and pressing the button while pressing the brake pedal even if the fob battery is dead.
 
This can not be true if you lost both key fobs. You should be able to get a set of new key fobs based on your VIN from your Mazda dealer after the verification of car ownership. More expensive and time consuming for sure, but no need for ECU replacement.
It was true.
You can ask your dealer next time you visit them and ask them a hypothetical question.
At least, it was true a few years ago. Not sure about recent years.

The 2nd fob programming needs one working fob (1st one) in the procedure.

If you have no fob, the ECU needs to be replaced.
It was like that.
It is likely for security concern.
 
Last edited:
It was probably due to bad contact rather than the capacity of the 2025.
My fobs of older Mazdas ('14 3, '16 6 and '17 CX-6) last about 1-2 yrs.
They all have the 2025s.
 
I agree. When the fob stopped working with a 2025 installed and I pulled the battery and put it right back in the Fob would start working again. The 2032 has a longer contact section and fits tighter in the Fob. Since I bought the car slightly used, the previous owner might have replaced the original 2032 with a 2025 for all I know. Glad it is working steadily anyway you look at it.
 
Surprisingly the key-fobs don't end up at the junkyard. The car owners(and or insurance companies) usually keep them and maybe sell them on internet. Either get a used keyfob off eBay and pay local locksmith to reprogram(dealership is expensive) or try the website www.keylessentryremotefob.com which we were gonna use for remotes for another non-Mazda vehicle. The aftermarket remotes were really cheap under $100 for the keyfob including the slot key. we got rid of car and no longer needed the extra remotes so haven't tried the site yet and can't comment on the product quality.
I bought a fob from keylessentryremotefob.com for under $90. It seemed to be slightly used, but considering the price I am not complaining. Small scratch on one side. I paid a locksmith $160 to program and it is now working fine as well as the original I already had. Quite a bit less than the quote from Mazda! The programming took about 30 minutes or so. As an aside I wonder if they have to mess with the ECU settings? I would think so. At any rate it might be psychosomatic, but I thought the car ran better after? Thanks for the tips!
 
Back