I have a 2021 cx5 and everything was working fine until I had pop a lock make me a spare key. I only received 1 key when vehicle purchased. Pop a lock purchased a new key fob and programmed it. Now I have this “keyless entry malfunction” error message. Everything works on either remote. I have tried disconnecting battery but that didn’t clear the message. Any suggestions?

 

Welcome to the forum

Ya so FYI DONT disconnect the battery to try to remedy electrical conditions on your year Mazda. Unless you completely know and understand what your are doing. You are likely to cause other problems.
Your keys need to be reprogramed again properly.

 

Thanks for reply. I’ll check the owners manual to make sure there are no special procedures. The locksmith has been called again. I’ll update after he contacts me. Just FYI, I have a degree in electronics.

 

You didn't mention if you had purchased your CX new or not. If it was new, you SHOULD have received two key fobs with internal keys. If not new, then maybe, maybe not.

You're saying that both fobs work perfectly but you still get an error message, and this message showed up after using the new fob?



"Ya so FYI DONT disconnect the battery to try to remedy electrical conditions on your year Mazda"

Looks like the battery was already disconnected, now what?

 

What about when changing the battery? You have to disconnect the old one to put the new one in. I didn't have any issues when I swapped mine out earlier this year in my '21.

 

I also replaced the car battery about 2 years ago with no issues.
But the issue I have is with the key FOB.

 

That is much different service procedure. It really takes longer then a couple minutes to change the main car battery. And the best way for most platforms over 2013 is using a memory battery so you don't loose current during the change that can cause problems.

Often times when DIY do the battery disconnect, they tend to touch the battery lead on the battery and disconnect it a couple or more times before getting it on the terminal or installing the fastener and unknowly cause a surge in the battery voltage through the electrical system. This can have a negative effect on several electrical parts that need the constant stabilized voltage

Not to mention this DIY method really does nothing as many think having to do with the ECU. While they think they cleared errors all they did was cause them to be moved to the ECU permanent file and the counters to add another click to the unresolved issue. A dealer or good technician can find the counters and see how long an unresolved problem has actually go one on. So this is also why telling a tall tail to a service shop about the how long a problem has been going on often they find you not to be totally truthful. Customer LIE all the time lol

[QUOTE=Gll;237202]I also replaced the *car battery about 2 years ago with no issues.
But the issue I have is with the key FOB.[/QUOTE]


How did you absolutely determine this. If you did the diagnostic testing, then you would have already solve your problem ???

The time you changed your main battery does not mean that your battery is in good condition. The ONLY way is to have it load tested. As for the time you changed it is not in any way an indicator of the actual age of the battery. It could be 6-12 months or more older from the manufactured date before you purchased and installed it.

 

Find a reputable dealer --pay the piper to get it done right - Sad - but common dealers sell used units traded in and never get the second key - or make a second one for the new owner -

 

Thats right and that's why they are called trade-ins used vehicles. No dealer is obligated to make addition keys and never has been. Wake up that is been pretty much the thing with used cars since the at least the 70's that I can remember. It's one reason why dealerships now lock their keys up and if a salesmen's or other dealership employee need a key, they must check it out.
Stick to your day job because posting less then accurate information is getting old
But I am sure you will have a snappy come back and I will be ready to respond to it. LOL

 

Wow, just wow.

"But I am sure you will have a snappy come back and I will be ready to respond to it. LOL"

Enough said.