Forester XT 15 Rear Boot running battery flat.

[Waynemarlow]

My Forester has been a right pain in running the Battery flat, not always just on occassion and always it comes down to the rear motorised boot not latching correctly, right from new. If the boot is not correctly closed, the rear boot will continue to use the Battery for some reason. In the States there has been a replacement control module which switches off the rear boot monitoring after 20 minutes, fitted as a general recall if the owner is having problems.

Here in the UK the dealer ( Bulldog Twyford ) is sticking their fingers up, saying you are not getting the vehicle serviced here, we will charge you to first look and diagnose the problem and then charge for the replacement parts. Fair enough I guess but this is a known problem, on their records from new and they were the supplying dealer. Bit off hand as I have had Scoobies for over 35 years on a continuous basis and I'm thinking that Bulldog may never ever get my business again.

So how do I get around the problem as I'm sick of having to replace batteries ( as soon as they get below 11 volts / fully discharged they are toast ) ? Is there anyway I can revert to a manual boot opener or perhaps upgrade that module ( if someone knows the part number please ) to the later part, at least it would switch off the power to the boot and I would be able to see the boot is open the next time I enter the car. Is there anybody who knows where the boot closed sensor is and how to cheat the system by making it always look closed. Any other ways I can get around what is totally spoiling the reliability of what should be a reliable and great vehicle ?  

Any help would be appreciated.

[Brack]

Looks like this chap found a way round it on his Outback.

 

[Justin Time]

Wayne.  Is the problem, or part of it, the fact the mechanical part of the latch isn't making contact with, and grabbing, the metal latch on the sill?  I ask, because if it wasn't locking onto that properly then the Battery would drain as it thinks the boot is still open.

In my Gen5 OB, when I want to leave the boot open for a long period, such as when camping, I trick the car into thinking the boot is closed when it's not, by using the karabiner trick (see Youtube) on the mechanical part of the boot. This stops the draining of the Battery (and also no interior light is on and I can see the car thinks the boor is closed because there no indication 'boot open' sign on the dash).

Have you tried this website https://www.subaruforester.org/  ?

The yanks sell and own a massive number of Subarus than in Europe so their owners' forums are great for info.

Best of luck.  Let us know how you get on. 

 

[Waynemarlow]

13 hours ago, Justin Time said:

Wayne.  Is the problem, or part of it, the fact the mechanical part of the latch isn't making contact with, and grabbing, the metal latch on the sill?  I ask, because if it wasn't locking onto that properly then the battery would drain as it thinks the boot is still open.

Yup, the issue is that the bootlid for some reason on rare occassions doesn't fully shut and within 48 hours the Battery is doomed. The Subaru dealer had a couple of goes at repairing it under warranty and when I pressed for a new opener under warranty, refused as I had missed a 12 month service despite doing lower mileage than the service schedule.

At that point, no warranty on a 2 year old vehicle, why bother with the premium cost of Subaru servicing. Not a happy situation.

I tried removing the lift arm from the actuator but failed to fully do the job and remove the power source. The vehicle wouldn't lock as it thought the boot was open. I guess I'll go full on this time and try the same as the above video.

Thanks all and keep any ideas coming.

[Brack]

If its the same kind of lock set up as mine - try pressing the tailgate release button twice when you open it (once for partial and again for full release) then the motorized closer might just close it properly for you...it works for me although mine is manual closing...worth a try though. 

Edited November 5, 2023 by Brack
Maybe a different lock 7 years on from mine.

[Waynemarlow]

Ok an update, after getting the wiring diagrams from Subaru ( thank you Subaru customer support ) the offending current draw was narrowed down to the rear boot. ( SBF No 8 feeds all the internal fuses near the steering column ).

On disconnecting both the lift mech and closure mech, much the same as far as current draw, but the vehicle wouldn’t alarm despite the boot being correctly shut.

All the wiring checked out so being left with only components I fitted a new rear sill latch and voila, the boot now shuts like a Swiss watch compared to the old mech and the stand by current is down to 0.07A’s. 

A note here, the alarm system is sensitive to anything moving, even ever so slightly on the side. If you are testing standby current, you will need to have the bonnet closed, stand still at the front, alarm the car and wait 30 seconds before the standby current will begin to drop. If you move at all the alarm will wake and begin to draw current. 
 

Another note, you can’t fit a manual sill latch, the bolt pattern in the tailgate is different.
 

Subaru U.K. advised that all vehicles post 2013 have been fitted with the updated rear boot controller and yet the rear sill latch for some reason wasn’t allowing the vehicle to fully shut down. A bit of firmware not working in harmony somewhere.