I have a 2016 CX5 and recently have experienced some dead batteries. Upon further testing I seem to be experiencing a parasitic draw.
I put a multimeter in series with the negative battery terminal and the current draw while off holds steady at 160-170mA.
I went through the process of removing each fuse one by one until I saw the current level drop to around 50mA before then settling even further to around 10mA.

As a result, I believe that the parasitic draw is occurring in the fuse F17 "Cabin.+B", with the description for "For protection of various circuits".
I was hopeful that this test would lead me to the specific component but I am unable to find anything online that talks about Mazda "Cabin.+B".

Does anyone know what circuits this protects or how to further diagnose the draw from this circuit?

Thanks!

 

I recommend putting that fuse back in, going back to the draw testing, pick up where you left off pulling fuses, and see what happens with each fuse pulled.

 

Hey m5xguy, thanks for the reply.
I should have mentioned that I did that with all of the fuses and with every other fuse the draw remains at the same level between 160-170mA.
The only time it dropped below that draw was when I removed the "Cabin.+B" fuse.

 

Did you replace the fuse with a new one?
Obviously, you will need a wiring diagram to determine what is tied to that fuse.
You'll need to purchase one or find a free one online.
You can try the website below for that, but they require that you add then to your safe list in any ad blocker software you have.
I have not done that and don't know what ads you will get.
Internet searches say the website is "safe", you can take that for what it's worth.
Engine Repair Manuals For Cars Free | Cardiagn.com

 

What you wrote above surprises me, because the schematic indicates that the CABIN.+B 50A fuse protects a large collection of circuit groups, and each one of those groups is immediately protected by another, separate fuse. So, regardless of where the parasitic draw is located, pulling all of the fuses one-by-one should eventually zero in on the culprit circuit group.

The only other thing I can think of is to run the complete draw test again, but this time wait for at least 5 minutes after pulling each fuse. Yes, that will take quite a bit of your time, but I can't think of anything else to suggest.