Ascent battery dies after 7 days - bad data from Dealer

[Beemer42]

My 2022 Ascent stands for a week or so at a time and suddenly one day the battery died. Charged it and measured it - Battery was rubbish and Subaru tested it and replaced it under warranty - hoorah! BUT a couple of months later (now out of warranty ) damn thing dies again after not being driven for 10 days. Now I did some measurements - charged it up and tested every couple of days. This "new" battery wouldn't charge to much over 12,5V - so first off the battery that the dealer out in was definitely not a premium one. After 7 days was down to 11,1V at which point starting the car became dicey. Took it to the dealer thinking that the replacement battery was C@@p and suggested it needed to be replaced under warranty. Dealer checked it and said battery was ok. MMM - Asked dealer to test the so called "Dark current" - that's the draw while the car is switched off. The dealer answered that they measure it at 0.19Amps! I made sure that this was not an error and the dealer insisted that this was "normal" as they "knew" from other cars that this was a normal draw! OK so math is not the dealer's strong point and I tried to point out that 190 mAmp draw will kill the average battery in about 8 days!
I may as well have discussed the theory of relativity. So went to the National Customer Service line and repeated my request for clarification on this massive Dark current number. Got absolutely blown off by them with a stupid answer to the effect that Customer Service does not have any technical or diagnostic knowledge and that I should refer to the dealer. I have been around cars for over 60 years and have never seen a dark draw much over 70 mAmp. Obviously the dealer doesn't have a clue about this or does not want to get involved in a difficult issue, so I must now try to suss out wtf is going on.
Anyone had a similar experience and maybe cast some light on possible solutions? Scuse the long drawn out post!

 

[Dick Foster]

Yeah that's pretty high alright but I've always heard it called parasitic drain.

Dark current was a form of noise or leakage in an imaging array when I was in the camera chip business. Haven't heard that term since I retired. It was the bain of people trying to make imaging chips with the CMOS process. It was hard to deal with and frustrated most efforts.

 

[dlc1965]

Pull the fuse for the DCM (might say Telli) 30 amp green fuse, see if you draw goes away. If so the dealer need to replace DCM.

 

[jcarufo]

Do a search on the DCM draw down issue and you will find your issue discussed at length. I found a YouTube video where detailed instructions were given to build a jumper that modified the DCM circuit from an 'always on' to on with 'ignition'. It totally solved our issue. Our Outback 'upgraded' battery typically was dead in 5-7 days. First time I tried this after being gone 2 1/2 weeks, our car started right up without hesitation. Everything else still works like it should too. If you remove the DCM fuse, the battery issue resolves, but there are stories of other things that stop working as well.
Here's the link I used:

Hope this resolves your issue. Dealing with the dealer is a joke. They all know the issue is really prevalent, but refuse to address it. This work around seems to do the trick.

 

[dlc1965]

Do a search on the DCM draw down issue and you will find your issue discussed at length. I found a YouTube video where detailed instructions were given to build a jumper that modified the DCM circuit from an 'always on' to on with 'ignition'. It totally solved our issue. Our Outback 'upgraded' battery typically was dead in 5-7 days. First time I tried this after being gone 2 1/2 weeks, our car started right up without hesitation. Everything else still works like it should too. If you remove the DCM fuse, the battery issue resolves, but there are stories of other things that stop working as well.
Here's the link I used:

Hope this resolves your issue. Dealing with the dealer is a joke. They all know the issue is really prevalent, but refuse to address it. This work around seems to do the trick.

Some of us Dealers really do care! I Pulling the fuse was merely a test, I did not expect them to leave it out. I cannot tell you how many people we have warrantied a DCM .

 

[Beemer42]

Pull the fuse for the DCM (might say Telli) 30 amp green fuse, see if you draw goes away. If so the dealer need to replace DCM.

Unfortunately nowhere in the fuse box under the hood does it mention DCM or Telli. However, when I pulled the 30A fuse marked VDC SOL, the parasitic draw dropped to 20mAmp and stayed around that - anyone have any info on what that fuse drives? I will dig around to try to find some info on the fuse layouts because there is squat in the owners stuff.
OK So found elsewhere on this forum that the fuse VDC SOL is linked to the rear tow hitch harness setup and that some after market hitches can and do have a controller that remains live when the car is off. Now I bought this Ascent second hand and it came with the hitch so have zero idea as to provenance or correct fitment as i have never actually used it.
Not even sure where to start looking for some sort of glitch in that system either. Anyone be so good as to point me in the rightish direction to start looking?

 

[jcarufo]

Some of us Dealers really do care! I Pulling the fuse was merely a test, I did not expect them to leave it out. I cannot tell you how many people we have warrantied a DCM .

The sad part is that it depends on the dealer. There is obviously a major DCM flaw when one dealer responds with, " I cannot tell you how many people we have warrantied a DCM." And you are only one dealer. When an owner comes to you with a dead battery after a period on non-use, do you immediately tell them it's probably secondary to parasitic power drain from a known DCM issue? I guess then, my question would be why you and your fellow dealers have not pressured SOA to address and resolve the issue? It's basically, if you own a Subaru, you (will) have an issue with the DCM. Driving your vehicle everyday tends to mask the issue, so many may not be totally aware or impacted. It may be years and a couple of unneeded replaced batteries before you are aware of a problem (ie. out of warranty). Go away for a week and park your car and you will see what everyone who has, lives with as the reality.
So how do you address your past customers that are a day, week, month, or year out of warranty? Do you also replace their DCM as a curtesy because you know there is a problem? Will the replaced DCM also fail over time? The problem isn't fixed, just postponed again for awhile. At least the gentleman that posted the video, took the time to share his expertise and experience to give us with sh**y dealers, an approach that addresses the issue in a very thoughtful and effective way. Since following his instructions, we are probably a dozen 'parked weeks' down the road with our car starting afterword like it should, every time. I feel fortunate to have found it.
Thank you for caring for your customers. JC

 

[bmart]

Pics

Words

 

[jcarufo]

T

Unfortunately nowhere in the fuse box under the hood does it mention DCM or Telli. However, when I pulled the 30A fuse marked VDC SOL, the parasitic draw dropped to 20mAmp and stayed around that - anyone have any info on what that fuse drives? I will dig around to try to find some info on the fuse layouts because there is squat in the owners stuff.
OK So found elsewhere on this forum that the fuse VDC SOL is linked to the rear tow hitch harness setup and that some after market hitches can and do have a controller that remains live when the car is off. Now I bought this Ascent second hand and it came with the hitch so have zero idea as to provenance or correct fitment as i have never actually used it.
Not even sure where to start looking for some sort of glitch in that system either. Anyone be so good as to point me in the rightish direction to start looking?

Take a look at my post and youtube link just two above yours. In that video, the DCM circuit is identified and addressed with an easily made jumper that turns the DCM circuit from 'always on' and draining to 'on with ignition'. It totally and immediately resolved our dead battery issues. It's also seemingly not effected any other system on the car. I realize that you have an issue with an Ascent and the video addresses a known Outback issue, but I doubt there would be a difference. I think the DCM fuse was #9 if I remember correctly. I hope you resolve your issue.

 

[Dick Foster]

Why is it that some folks looking for help can't or won't read to find a cure and help?
Have our schools failed that miserably? Are they illiterate?

 

[bmart]

Yes. I always poke the bear a little asking if they want me to search for them because they're too busy...but I shouldn't be.

 

[Beemer42]

T

Take a look at my post and youtube link just two above yours. In that video, the DCM circuit is identified and addressed with an easily made jumper that turns the DCM circuit from 'always on' and draining to 'on with ignition'. It totally and immediately resolved our dead battery issues. It's also seemingly not effected any other system on the car. I realize that you have an issue with an Ascent and the video addresses a known Outback issue, but I doubt there would be a difference. I think the DCM fuse was #9 if I remember correctly. I hope you resolve your issue.

This may be true for the Outback but definitely NOT for my Ascent. There is zilch mention of a DCM fuse or circuit anywhere and from what I am now seeing, the problem may well be the hitch circuitry. I am going to do some tests pulling the power to that to see if that is the culprit.

 

[jcarufo]

I found this Reddit discussion that you might find of interest. Per the chart referred to and the addendum, You have a Gen 2 DCM in your Ascent. There is also a Service Bulletin regarding a battery issue with suggested replacement, that may apply as well. The links to the reddit posting by a Subaru Service person and the Battery bulletin are below.
Hope they help in your resolution.
jc

https://www.reddit.com/r/subaru/comments/15v7a0j/dcms_battery_settlements_and_dark_draws_oh_my

https://static.nhtsa.gov/odi/tsbs/2023/MC-10232218-0001.pdf

 

[Beemer42]

My 2022 Ascent stands for a week or so at a time and suddenly one day the battery died. Charged it and measured it - Battery was rubbish and Subaru tested it and replaced it under warranty - hoorah! BUT a couple of months later (now out of warranty ) damn thing dies again after not being driven for 10 days. Now I did some measurements - charged it up and tested every couple of days. This "new" battery wouldn't charge to much over 12,5V - so first off the battery that the dealer out in was definitely not a premium one. After 7 days was down to 11,1V at which point starting the car became dicey. Took it to the dealer thinking that the replacement battery was C@@p and suggested it needed to be replaced under warranty. Dealer checked it and said battery was ok. MMM - Asked dealer to test the so called "Dark current" - that's the draw while the car is switched off. The dealer answered that they measure it at 0.19Amps! I made sure that this was not an error and the dealer insisted that this was "normal" as they "knew" from other cars that this was a normal draw! OK so math is not the dealer's strong point and I tried to point out that 190 mAmp draw will kill the average battery in about 8 days!
I may as well have discussed the theory of relativity. So went to the National Customer Service line and repeated my request for clarification on this massive Dark current number. Got absolutely blown off by them with a stupid answer to the effect that Customer Service does not have any technical or diagnostic knowledge and that I should refer to the dealer. I have been around cars for over 60 years and have never seen a dark draw much over 70 mAmp. Obviously the dealer doesn't have a clue about this or does not want to get involved in a difficult issue, so I must now try to suss out wtf is going on.
Anyone had a similar experience and maybe cast some light on possible solutions? Scuse the long drawn out post!

SO I found the problem!! Its the hitch. The hitch was resulting in a draw of around 200mAmp and once I pulled the fuse shown in the pic this dropped to 25mAmp. The dealer "expert" technician's claim that the 190mAmp draw they measured was "normal" for the car was simply BS. Another individual who remained anonymous as he is a Subaru employee assured me that when they performed the parasitic draw test as set out in the attached service bulletin ( https://static.nhtsa.gov/odi/tsbs/2021/MC-10201052-0001.pdf) , the draw should not exceed 50mAmp - which is precisely the number set out by Toyota and BMW. Makes me have some serious doubts as to the competence of the local dealer ?
As I rarely use the hitch and as it seems that the circuit thus killed does not serve any other function, I can leave the fuse out and keep it in the glove box to be inserted when needed. I would like to get my hands on a wiring diagram for the hitch - which may be an OEM one (I got the car with it installed so have no clue as to source) -and fix the issue. So if someone has some insight , feel free to drop a line! I enclose a picture showing the fuse for the hitch as well.

 

[bmart]

Makes me have some serious doubts as to the competence of the local dealer ?

Dealerships are called stealerships for a reason. High prices and worst staff.