2016~2021 Battery drain in 2020 Mazdas

Went to jump in my less than 1 month old CX-9 this morning and it was dead. Neither remote would work. Had to key in manually. No lights, no audible alerts, nothing. Had AAA jump it and ran it up to the nearest Mazda dealer. By that time, the battery was charged. But here's the scary part. When I told the mechanic what was going on, his reply was, "Welcome to the club". Apparently there is a problem with battery drain in some 2020s, especially the CX-9s and CX-5s. It has even happened to some cars sitting on the lot. The mechanic estimated that they've seen a dozen cars with the same issue. They are passing the info on to Mazda so they can seek a remedy, but nothing yet. Hopefully a simple fix.

Anyone else?
 
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Mazda CX-9 Grand Touring 2016
It's not just Mazda. A friend had a Subaru buy-back with the same problem. I think it is some electronic problem from a supplier. In any case, do not accept a replacement battery as a fix. Demand that the dealership show you the current draw, with an ammeter, with the car shut off. You'll find that something is drawing a good battery down. It might be a stuck relay or maybe something else. In any case, it's Mazda's problem, not yours.
 
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Ottawa, Ontario
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17 Mazda 6 GT
I read somewhere that Honda CR-V's have the same issue. Not sure if they found a fix yet.
Modern tech. Ain't it grand.
 
It's not just Mazda. A friend had a Subaru buy-back with the same problem. I think it is some electronic problem from a supplier. In any case, do not accept a replacement battery as a fix. Demand that the dealership show you the current draw, with an ammeter, with the car shut off. You'll find that something is drawing a good battery down. It might be a stuck relay or maybe something else. In any case, it's Mazda's problem, not yours.
"buy-back". That's a scary word. Certainly hope it doesn't come to that. I stumbled on a thread yesterday regarding an 08 model with the same issue. It was eventually connected to a bad relay to the rear defroster. I'm not an electronics guy, so I'm not sure what a relay would have to do with battery drain, but I guess it did/does.
 
I read somewhere that Honda CR-V's have the same issue. Not sure if they found a fix yet.
Modern tech. Ain't it grand.
The knock on the CX-9 was that it was getting long in the tooth since the current model was introduced in 2016. I actually viewed that as a positive thinking that would improve the chances of purchasing a proven, reliable vehicle. Ironic I guess. I did my research and didn't come upon any similar issue with 2016-2019 models. Odd that it's popping up in the 2020s.

What is Mazda's rep with stepping up in circumstances like this? I know some manufacturers are more ethical than others when it comes to backing their customers and not requiring ridiculous measures to get them to act.
 
Depends which region you are in. Mazda dealers in canada are pretty good. In the usa not as much apparently. But i would be amazed if mazda would do buybacks for battery drains instead of diagnosing it properly and fixing the problem.

Mazda can be pretty good sometimes ( someone here just had their engine replaced for free on their 2015), sometime not so much (people getting the turn around for from the dealers sometimes.)
 
Depends which region you are in. Mazda dealers in canada are pretty good. In the usa not as much apparently. But i would be amazed if mazda would do buybacks for battery drains instead of diagnosing it properly and fixing the problem.

Mazda can be pretty good sometimes ( someone here just had their engine replaced for free on their 2015), sometime not so much (people getting the turn around for from the dealers sometimes.)
Makes sense. A classic YMMV, I guess. I'll start with the dealer service department to see if I can get a proper diagnosis and troubleshoot and take it from there. Sheesh.
 
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2010 CX-9 GT
"buy-back". That's a scary word. Certainly hope it doesn't come to that. I stumbled on a thread yesterday regarding an 08 model with the same issue. It was eventually connected to a bad relay to the rear defroster. I'm not an electronics guy, so I'm not sure what a relay would have to do with battery drain, but I guess it did/does.
All the high current loads are switched on/off using relays. The switches in the cabin are all low current circuits for safety and weight reasons. When you press a button in the cabin, it energizes the relay, which energizes the high current load circuit (headlights, heaters, etc.). If a relay sticks, the load stays on and drains the battery.
 
Went to jump in my less than 1 month old CX-9 this morning and it was dead. Neither remote would work. Had to key in manually. No lights, no audible alerts, nothing. Had AAA jump it and ran it up to the nearest Mazda dealer. By that time, the battery was charged. But here's the scary part. When I told the mechanic what was going on, his reply was, "Welcome to the club". Apparently there is a problem with battery drain in some 2020s, especially the CX-9s and CX-5s. It has even happened to some cars sitting on the lot. The mechanic estimated that they've seen a dozen cars with the same issue. They are passing the info on to Mazda so they can seek a remedy, but nothing yet. Hopefully a simple fix.

Anyone else?
hi, i have a 2020 CX-9, bot it in Feb. Last month my battery died and had to jump start it. Today (june 26), my battery died again for the 2nd time! I did not leave any lights on or doors open, maybe it was the 2 iphone chargers that were plugged in, but were not charging any devices. Calling service today.
 
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Mazda CX-9 Grand Touring 2016
Don't let them just put in a new battery and send you home. Have them load-test your present battery to determine it's health. If it is actually bad, OK, new battery time (but that shouldn't happen). If the battery tests good then have them check the current draw from the battery when the car is off. Something is pulling the electricity out of the battery when it should not (the car is off), and they need to find it & fix it.
 
dealer mentioned it could be the back gate module. They recently had 2 cars come in with similar issue. Dropping car off today for a full evaluation. will let u know what happens.
 
hi, i have a 2020 CX-9, bot it in Feb. Last month my battery died and had to jump start it. Today (june 26), my battery died again for the 2nd time! I did not leave any lights on or doors open, maybe it was the 2 iphone chargers that were plugged in, but were not charging any devices. Calling service today.
Sounds familiar. Doubt it was your chargers, but you never know.
 
Thanks for the post. Had you heard of anything like this before discovering this reddit post? Trying to determine if it is a common problem or fairly isolated. Another poster earlier said his dealership suggested a couple 2020 models had a "back gate module" issue that appeared be the culprit.
I joined the forum this week. I like to thoroughly research my vehicles before I buy them.

This seemed to be the 'major' issue with the car - some USB ports.

What is the back gate module?
 
Hi, update on my CX-9 battery drain. The dealer said the rear tail gate module is pulling power when car is off. They have seen this defect in a few cars, replacing the part-under warranty. Battery seems fine, dealer will run a test with new module and will replace if needed.
No mention of any USB port issues.
 
Hi, update on my CX-9 battery drain. The dealer said the rear tail gate module is pulling power when car is off. They have seen this defect in a few cars, replacing the part-under warranty. Battery seems fine, dealer will run a test with new module and will replace if needed.
No mention of any USB port issues.
Thanks for the update. Which part of the warranty covered this part? The bumper to bumper?
 
Vertigo88, yes the 3 year/36k mile bumper to bumper warranty covers this repair. Customer service excellent so far, i dropped the car off on friday afternoon, they put me into a new CX-9, received a call this morning for update, shd be done in a few days (waiting for part to come in).
 
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