Hi chaps.

I've had my WRX for a few months now and the M30 is a real pain in the ****.

I wonder if anyone on here can tell me how the system can be removed? I am sure it can be done after seeing a lot of hints to the fact online, but no one goes into any detail about it. Most I have seen is that there are some wires that need re-joining under the dash?
I suppose you won't want to post it on here for all to see, but any help via PM would be great?


The thing works perfectly at home, but when I go into town(shops, petrol station ect) it works very intermittently which best case leaves me sitting in the car unable to start for 5 minutes or having to open the doors with the key and having the alarm go off....
Now I've read up on this and reckon its due to it being a **** system and being blocked by interference ect
I've replaced the batteries in the fobs and changed the manual code to one I can remember, so I can use that, but its still a pain.
I want to use it for long journeys at weekends instead of the work van, but don't want to be stranded away from home because of the Sigma!
It also killed the battery which cost me £60...



Many thanks, Ben

 

So perharps not wisely(since I have to use the car tomorrow), I started to attack the M30 to see if I can remove it.
I took the trim off under the drivers dash, steering column shroud and fuse box. The M30 ECU is bolted just under the instrument cluster up under the dash in a steel case.
I cut into the M30 loom and started tracing the wires and found a slice into the OE loom just at the factory keyless entry module and before the plug on the ignition barrel loom.
Here are a couple of pictures:


M30 Sigma alarm splice at Subaru module




M30 Sigma splice in ignition loom




I have no idea what the splice does at the keyless entry module, but the one in the ignition loom is the starter trigger.
As you can see I connected the original impreza loom and turned the key with the Sigma M30 immobiliser active and the engine will turn over now, but will not start. I cannot here the fuel pump running when so I assume there is another M30 splice into the loom preventing this.
Does anyone know where this spice is as I can't seem to find it without further splitting the loom, which is a PITA?

Any help will be greatly appreciated as I feel I am nearly there with getting rid of this terrible alarm!

Cheers

 

A couple of other things to note is that the starter motor trigger wiring used by the Sigma is a lot smaller gauge than the OE Subaru wire and the sneaky **** who installed the M30 cut a few inches out of the loom so you won't be able to solder it together without adding some more wire!

 

So I have done a bit more digging and the splice the fuel pump is in the loom that runs along the bottom of the drivers door. They have cut a massive length of wire out of the OE loom. There is also a hellish amount of Sigma wires piggy backed onto other Subaru wires that I have no idea about so left them alone, possible the central locking?

Anyway the car now starts with all three cut Subaru wires bridged which is a great success!
I think I will leave the M30 system wired in as well seeing as the car starts and runs both with the Sigma activated and deactivated so I can still set the alarm if the ECU doesn't fail due to radio signals.
Just got to find 6 miles of insulation tape and get the soldering iron out now



Sigma M30 fuel pump splice.

 

awesome way to advertise to all car thieves where its connected in lol

 

I am sure they already know where its connected if they are any good and if not good luck trying to do all that in public with the alarm going off?

Oh and you still need the subaru key with the chip inside.

 

Ben you are a legend honestly!!!! Your thread saved my backside!!! Been looking and looking how to solve this alarm problem, posted threads but no one helped. I really appreciate you posting this information saved me a lot of money!

Thank you 😀

 

tbh the sigma is a **** alarm,

i cant park near asda or currys as the thing wont turn off

 

i totally agree dude... It's hopeless.. it gave me a lot of headache so it had to go..

 

that`s only the M30 . . . . the S30 and up is spot on.

 

Maybe s30 is better... But m30 is a piece of junk it killed my battery aswel, so p***** off with it!

 

lol so the batteries that must be over 10 years old died(this is what drained your battery), just like on a tracker, you dont slag the tracker off for old batteries . . .

 

It was a new battery dude.. Didn't know it was this alarm that caused it to die in the first place

 

It was prob a decent alarm when it was new, but the signal frequency issue is a real killer and makes the car unusable in certain places.

Glad this thread helped, when I was looking I couldn't find any help either.

 

It really helped Ben... It was the only thread online that helped, i am glad that you posted this mini guide