After 5 years of owning my '18 CX-5 now with 40,000 miles, it had never had that system failure sign coming out frequently with these Summer 100 F temperatures, and this happens after I start the car that has been parked under the sun for several hours, even the exterior temperature is showing a wrong reading. I have seen failure signs showing in the dash from a strong sun glare or from cold weather frost, that seem kind of logical to affect the safety features but not by high heat weather. Also I have noticed that the automatic changing of high beam/low beam has less tendency for the auto changing of the headlights. I also noticed that when driving with the cruise control setting sometimes my car begins to brake when the vehicle on front reduces the speed and sometimes it doesn't do it under similar conditions, I don't trust 100% the accuracy of the system. Seems like if the vehicle gets older those safety sensors tend to fail, I haven't seen that happening in other vehicles that I owned. I'm surprised!

 

Well, you have to many problems that are not associated with one monitoring system or connected together. This is beyond advising from members on a forum!
You need to have the ECU health check possible flashed with the last and or most current update. First you need to have the battery load tested. Then you need to check all the battery connection both at the battery terminal and at their first mani connection source. Then you need to have the temperature sensor in form to the AC condenser checked, the list gooes on!!!!!!!

Wherever you take your Mazda you need to check and be sure that the service shop will have a currently certified Automotive Technician diagnosis your problems.

ASE

 

I already have a new battery on my CX-5.

 

What does that actually mean? LOL

Please read what I recommended again.

A new battery does not mean it is a good battery!!!!!!!!!!!!!!!
Before you can do any diagnostic on the electronics on any vehicle the first thing that needs to be done is assess the battery and the battery connections.
This is done by LOAD TESTING a fully charged battery. A fully charged 12volt battery should be at least 12.5 stabilized voltage to do a proper battery load test.


For all that read this thread I will again try to make some understand about the term NEW BATTERY

New battery only really means that you purchased a product unused and hopefully was never connected to anything other than a Load Tester or charger. Thats really all when describing a NEW BATTERY it means>
The date sticker on the battery DOES NOT INDICATE the battery age of manufacture.
Nor does the bar code on the battery.
Both those are for the purpose of the retailer's warranty starting date.
The batteries actual manufacture date is in a code melted in the top cap on the side of new batteries. The only way to decode that date is to go to the manufacture of that battery which may not necessarily be the name brand on that battery.

All electrical issues start with first confirming the power supply system is in good health!


ASE