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
By
Mr B ·
