Hi, my 2006 Forester is totally immobilsed.

Been off road for a couple of months, and was turning it over until the very cold snap a few weeks ago, battery died. It needs to go for MOT but will move on to my property and SORN (not an issue).

Car is immobilised but I can gain entry by key. Central locking does not work remotely by fob.

Ive put a brand new car battery in. The car was completely without power for a few weeks. New batteries in both original fobs. Windows and lights work.

On insertion of key in ignition, indicators flash rapidly and alarm will trigger after 30 seconds, can only turn off alarm by turning off ignition.

I have original silver key code stickers. The code might have been changed by previous owner - I had no need to use before battery change.

I believe the alarm is a Thatcham sigma system with the multifunction keypad and i have original Subaru paperwork including ECU serial no.

Its a second vehicle bought because of memories of another Forester years before and has generally been reliable, and body is in great condition as is interior but probably not worth a lot, and nothing in current state so I just need to understand costs to balance whether it is economically viable to fix this issue before I start other work - and how to/what do I do next?

Local-ish auto locksmith doesnt want to touch Subaru and another wont give any estimate before arrival. Im in a town with no nearby Subaru specialist.

Can you advise how to reset keyfobs/code to immobiliser and alarm / solve the problem?

Thanks in advance.

If it were me I would try every sequence in turn and ensure that I am sat in the drivers seat with all doors and boot/bonnet closed.
Sometimes its a case of trying different variables and seeing if the outcome changes
Please let us know how you get on with it all

I will keep trying. Interesting comment as i have had bonnet open. Thank you-I will close and retry.

to be honest I do not know what im doing. I recall my first forester and having to put a pin into keypad but that was with the seller. So long ago Ive forgotten sequences and do Inuse star button or hash before/after?

Is there a handy guide on the internet somewhere to getting keyfobs and alrms going ?

Ive tried searching through the subaru youtube videos. Most not for 2006 era vehicles, or for UK variants.

Reality is it not that big an issue overcome one way or the other .
Options are disabling the sigma m30 and bypassing immobiliser circuits (rejoining wires the 2 immobiliser circuits spliced into) .
Trying to get the current Sigma working to some functional extent again or replacing the modules with known working used ones (needs be supplied with pin code and/or working fob allow easy programming).

No need be a specialist in Subaru as this System is basically added after production line assembly and Sigma systems used on many vehicles in that era including a lot of euro cars .
Basically any fairly competent auto electrician, alarm installer or decent mechanic can do this work as it nothing fancy and all you really need is a brain and a multimeter, wiring info is helpful but not a must .

What I would do is do few basic things see if can get alarm to function, main thing that goes bad is the siren that located under the wiper plastic trim and sits in the cowl space, this has a P9 rechargable battery inside and they go bad and leak and decay the siren board causing various alarm function issues, just unplug the wire that goes to this siren and test alarm, Also test alarm by having ignition key on and pressing fob button and see if that turns immobilser off ! if does alarm may start function normally again if lucky .
You can leave siren unplugged and only issue is you get no siren tones but all will function if rest of system good .

If system seems totally unresponsive simplest option is bypassing the Sigma alarm and that pretty quick job to do, only downside is loose the remote central locking as sigma alarm install removed the factory subaru remote locking .

The Sigma alarms are nothing but potential problems at 20 years old as it euro made crap, all the Subaru Japan electrics and electronics will be fine and they all independant of the Sigma (besides remote locking) .

Even with the Sigma bypassed you still got the Subaru factory transponder key chip immobiliser and that good enough on an old basic Forester . Modern car thieves be lost at trying deal with a car with a physical key and a mechanical handbrake lol .

M30 document attached which might be helpful and does include info on pin code use. changing pin code and programming remotes .

m30.pdf

2 hours ago, Mr B said:

Reality is it not that big an issue overcome one way or the other .
Options are disabling the sigma m30 and bypassing immobiliser circuits (rejoining wires the 2 immobiliser circuits spliced into) .
Trying to get the current Sigma working to some functional extent again or replacing the modules with known working used ones (needs be supplied with pin code and/or working fob allow easy programming).

No need be a specialist in Subaru as this System is basically added after production line assembly and Sigma systems used on many vehicles in that era including a lot of euro cars .
Basically any fairly competent auto electrician, alarm installer or decent mechanic can do this work as it nothing fancy and all you really need is a brain and a multimeter, wiring info is helpful but not a must .

What I would do is do few basic things see if can get alarm to function, main thing that goes bad is the siren that located under the wiper plastic trim and sits in the cowl space, this has a P9 rechargable battery inside and they go bad and leak and decay the siren board causing various alarm function issues, just unplug the wire that goes to this siren and test alarm, Also test alarm by having ignition key on and pressing fob button and see if that turns immobilser off ! if does alarm may start function normally again if lucky .
You can leave siren unplugged and only issue is you get no siren tones but all will function if rest of system good .

If system seems totally unresponsive simplest option is bypassing the Sigma alarm and that pretty quick job to do, only downside is loose the remote central locking as sigma alarm install removed the factory subaru remote locking .

The Sigma alarms are nothing but potential problems at 20 years old as it euro made crap, all the Subaru Japan electrics and electronics will be fine and they all independant of the Sigma (besides remote locking) .

Even with the Sigma bypassed you still got the Subaru factory transponder key chip immobiliser and that good enough on an old basic Forester . Modern car thieves be lost at trying deal with a car with a physical key and a mechanical handbrake lol .

M30 document attached which might be helpful and does include info on pin code use. changing pin code and programming remotes .

m30.pdf

Mr B, many thanks for response.

An auto electrician (via email) has advised removing unit and a helpful call from Subaru Replacement Key Services seems to confirm alarm unit ECU is dead ?? >>

>>No LED in dash, no light flashes on keypad when inputting digits before key inserted. When key inserted the keypad light flashes several times on each digit entry.

Alarm DEFINITELY working. its loud and annoys neighbours and puts me off trying to do anything.

If I can get a replacement unit is it an easy swap out ? I dont possess a multimeter but inexpensive. Im not overly technical, or experienced. If replacement failed, Id go to a bypass route and sacrifice remote central locking.

Currently only the drivers door is locked by key…

As immobiliser system appears completely unresponsive but alarm sounds what would you recommend next?

Thanks

As mentioned before you can buy a used alarm main unit and plug it in and program your fobs to it and set a new pin code for it if so wished.
Only plus with that is remote locking be functional again .
Downside is you still dealing with 20 year old european electronics and as it basically can leave you stranded it best pulled out and binned as saves same issue twice (siren board corroded/faulty by leaking P9 battery being super common).
I done repairs both ways for customers (option tended to be driven by their preference on alarm and locking). you can add a remote locking system if pull alarm but that adds cost .
A working M30 used module is cheapest fix with everything same as owners already use to .
You can find used M30 modules pulled from Subarus for around 80 to 150 quid, it must come with pin or a working keypad ( I like a keypad with it as then you got a third keypad that can be used for parts in your key should one of yours fail and it generally easier programming using an existing remote than using pin code) .

You got options and none are technically difficult or needs specialist equipment thus the cost to resolve it either way is not crazy money .
If you half competent and can google info you could swap alarm module or even bypass it to get running as it really nothing more than cutting and joining some wires ...