2019 CX-9 GT 1.9A parasitic draw, fuse found, next step?

[ramahon]

Location: Phoenix, AZ

Hi all. Trying to avoid the dealership like the plague.

Going on ~2 weeks now, my wife's CX-9 hasn't kept a battery charge. Battery was checked good by a shop on the initial instance and I've mostly had it on a tender when we weren't using since then. I ought to check at a shop again if it is still holding enough charge. If not on the tender, it will 100% not start after sitting overnight. In fact, it had a full charge this afternoon...my wife took it out for a 15 min drive, 1 hour appt and it wouldn't start on retry.

Charges to: 12.6
Alternator to: 14
Meter connected in series: 1.9a draw (after sitting for 30+ minutes).
---> Removing Fuse10 (Interior Box), 15a: drops to .01a (after ~45seconds).

Looking for advice on next steps. Connects to the audio system, not finding any tsb related.

Thanks!

 

[roundle1979]

Read a lot about 2019s and 2020 with a tailgate module causing parasitic drain. Good thread here:

S

2016~2023: Thread 'Battery drain in 2020 Mazdas'

Jun 24, 2020

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...

• scottland7
• Replies: 80
• Forum: CX-9 General

Also, I have a 2018 CX9 GT and I've never had a battery make it longer than 3 years. I think the battery's under-sized for the various electronics (front and rear heated seats, Bose stereo, etc) but that's just my theory. I' started buying Interstate Batteries at Costco who replace without asking questions.

 

[ramahon]

Thanks for the reply @roundle1979. Ive seen the large threads on the tailgate, hope / wish I’ve misdiagnosed and it is that issue.

Unfortunately, I’ve hit a dead end and im dropping it off with Mazda this morning.

 

[roundle1979]

Thanks for the reply @roundle1979. Ive seen the large threads on the tailgate, hope / wish I’ve misdiagnosed and it is that issue.

Unfortunately, I’ve hit a dead end and im dropping it off with Mazda this morning.

They figure it out?

 

[ramahon]

I’ve gotten nothing back from Mazda other than a free loaner. Not necessarily the optimal time to bring in a car for service. I’m expecting an update by 10a tomorrow.

 

[Barlo1]

Waiting for a tow as we speak with the exact same issue - going on 2 years now. Would love to hear any update you have. Thanks!

 

[ramahon]

Unfortunately, Mazda claims they were unable to replicate. They had it for 5-6 days. Car hasn’t given us issues in since. The only thing that we were guilty of was leaving the fob in the car when in the garage overnight. Although, during testing I did remove it.

My only thought is that my original battery was actually bad and the weak battery was unable to fully put things to sleep? (I’m having to convince myself of this).

 

[Barlo1]

Thanks for answering so quickly. We are on our second battery and now the alternator seems to have been affected. Strangely enough, a previous tow truck driver told us that some of the mazda fobs are so strong, they can cause a drain. We recently put new batteries into our fobs and I'm kicking myself that I haven't bought a faraday pouch to put them in. But seriously tired of this.

 

[GrampaSlade]

There's power to this fuse/circuit when the car is off? NVM, of course there is.