2018 Forester with 6,000 miles, 2 dead batteries, dealership can't find problem

dbs2018subfor

Brand new Forester, 1st service trip to Matthews Subaru, I informed dealer service dept the battery had difficulty starting and there were some issues with various buttons on the vehicle, like the back liftgate opens at times, but not other times, passenger window doesn't work from driver side...they installed a new battery, telling me that sometimes when the cars come from manufacturer they have weak batteries. 1 week into the new battery, the car dies. The dealership has had the car 3 days, wants to keep it for another week and say they can't locate the problem. A brand new car and I have told them I can't trust it and want a full refund...to which they replied, that's not as simple as you might think! I have just read 8 pages of the same issue other customers are having. Why isn't Subaru doing anything about this issue???

Mr_Shiftright

That's too bad. It might be that the vehicle is too new to have generated any TSBs yet to guide the dealer toward a solution.

Seems to me that they could at least verify that you DO have a parasitic drain on the battery, even if they don't yet know the cause of the drain. You might ask them if they've even gotten that far. If they say no to that, then they probably haven't even looked at it yet.

If they have verified the parasitic drain, then that could legitimately take some time to track down. Sometimes there are various modules that don't shut down when they are supposed to---but sometimes they DO shut down--so the test equipment has to be on the car when the problem is actually happening.

I would agree with the dealer though--you aren't far enough along with this problem (yet) to invoke the Lemon Law for your state.

roadburner

If they gave you a loaner just keep driving it and let the dealer figure it out. You aren't anywhere remotely close to having the vehicle declared a lemon.
When I worked at a BMW dealership and we had trouble isolating an issue we simply gave the client a loaner that was equivalent or better to his/her car and told them we'd call when we had the issue solved. One time it took a Service Advisor and myself four days to figure out what was going on with a flaky telematics module in an X5-
but the customer was not inconvenienced and the problem was resolved.

xwesx

What type of vehicle did you drive prior to this one?

I ask, because I know several people who previously owned significantly older vehicles, and they had a similar issue with new vehicle purchases. In all cases, the primary issue is due to driving habits (combined with the new technologies). On newer cars, there is constant small drain on the battery, and it is much more significant than the small drain older vehicles experienced.

If your commute is short (maybe five miles or less), and you don't use the vehicle much other than that, you are going to draw more juice from the battery overall than it can charge into it. Ergo, you will end up with a "dead battery" before too long. If your battery charge is weak, you may notice some other features not working well with the vehicle off.

In all cases of people I know, adding a "permanently installed" trickle charger to the vehicle and plugging it in overnight once a week (such as Friday night after you get home) solves the issue. Adding a deep cycle battery, which is designed to handle draws better than starting batteries, can help with the problem as well.

If there is a problem with the car, it might be intermittent. I have a 2013 Forester, and, every once in a while, the fuel pump does not shut off with the vehicle. It is a quiet whirring noise that may go unnoticed, but it will kill the battery if not detected within a few hours. I imagine it is bad for the fuel pump, too! Simply switching the car to the 'on' position, then 'off' again, succeeds in turning off the pump. I had no luck resolving the issue with Subaru because they just could not replicate it. To be fair, it does only happen once in a while. Sometimes it will do it more than once in a week, and sometimes it will go for many weeks with no issue at all.

macman4

I concur with the previous comment'r 'XWESX" Gone in garage late night twice now and heard a low motor noise coming from the rear of our 2018 Forester. Sounded like a small air compressor or electric motor. Getting down it was prevalent between the wheel well and tire. Only motor in that area is the fuel pump. Started car and shut off, pumped stopped running. I called local Subaru Dealer and service writer stated over the phone "Yea, they do that sometimes" I'm pursuing this with Subaru as I know fuel pumps are not cheap to replace and I don't need a dead battery. It's the wife's car and I know who's getting that call if it won't start. If my vehicle was outside I don't believe I would have heard the pump running. Only in a very quiet garage. I may be back her depending how Subaru handles this looking for others experiencing this. Sounds like the relay that energizes the pump is not opening after power is shut off. Any other thoughts on what to make the dealer check out and look for?

thecardoc3

What you heard running was not the fuel pump, it's  part of the evaporative emissions system. The pump you heard puts a small amount of air pressure into the fuel tank and carbon cannister to test for leaks.The test runs after the car has been shut off for a few hours and is normal.

roadburner

If it was the fuel pump you would definitely hear it- quiet garage or not.

thecardoc3

A fuel pump if it stays running will draw somewhere between six to twelve amps of current and would completely  discharge a battery in a single night. The DMTL (diagnostic module tank leak) only draws about 200 milli-amps and typically runs for less than five minutes. 

xwesx

Discharge battery in a single night? Yep, that sounds familiar!