Looking to get this sorted as it's totally doing my head in, any time it's windy my alarm goes off it's nut and it's been the same through different batteries that have been fitted, I have to try and park between 2 cars anytime it's windy to stop it happening........ I have no idea where to start with a problem like this but know I need to do something, any advice appreciated

 

Cant you dis arm the interior sensors for a few nights, see if its that?

 

Arming the Security System Without Ultrasonic Interior Protection*
Warning: Impreza and Forester models from 2003 model year and Legacy models
from 2004 model year are equiped with double-locking doors. People should not be
left inside these vehicle s with the alarm armed under any circumstances. When
armed, the vehicles doors double-locked automatically and cannot be opened
internally! If armed in error, with an occupant in the vehicle, the system should be
disarmed and a door must be opened and shut to prevent auto-rearming and
locking occuring.
Arming the security system without ultrasonic interior protection will be necessary, yet still
provides limited protection, if you wish to leave animals inside the secured vehicle or the
windows/sunroof open whilst the vehicle is left unattended. Sensible safety precautions
should be exercised if considering these actions! To do this:
Turn the vehicle s ignition on,give the radio transmitter button a quick press.
The dashboard mounted LED will flash once.
Turn off the vehicle s ignition immediately.
Vacate the vehicle closing all doors, boot and bonnet.
Give the radio transmitter button a quick press, whilst standing near the vehicle.
The security system will acknowledge arming with 8 flashes of the vehicle s hazard
warning lights, instead of the normal 4. The doors will double-lock as normal.
Ultrasonic interior protection will be restored the next time the security system is
armed in the normal way.
* Also possible using the multifunction keypad. See page 11 for details.
Excluding Ultrasonic Interior Protection (Option 2 on the keypad)
Arming the security system without ultrasonic interior protection will be necessary if you
wish to leave people or animals inside the secured vehicle (sensible safety precautions
should be exercised if considering this action!). This facility may also be used to provide
limited protection of the vehicle if left unattended with the windows and/or sunroof open.
To do this turn on the vehicle s ignition, give the radio transmitter button a quick press,
type 2 on the keypad and immediately turn off the ignition. Vacate the vehicle, closing all
doors, boot and bonnet. Now arm the security system in the normal way.
The security system will acknowledge arming with 8 flashes of the vehicle s hazard
warning lights, instead of the normal 4.
Ultrasonic protection will be restored next time you arm the security system in the normal
way.

 

 

Will give both a try, just seems very sensitive to wind round about the car

 

Had similar issues with mine. It is a 2003 JDM so none standard alarm (so I believe). With mine the sensitivity was adjusted on the physical alarm (in engine bay) manually. It was prior to me owning the car so I cannot add more but worth mentioning all the same. Hope you get it sorted.

 

This happened to me with an astra i used to own, alarm would go off for no obvious reason, turned out it was
the air freshener hanging from the rear view mirror moving about and triggering the sensors.

 

Seems to have done the trick bud cheers

 

As mentioned, some (most?) alarms have some kind of manual sensitivity adjustment - usually located on the actual hardware (normally mounted in the engine bay).

So you might be able to reinstate the interior sensing facility, if you first turn the sensitivity down. Trial and error adjustments maybe be required.

 

Sigma M30 alarm
Note regarding ultrasonic operation and adjustment:
The ultrasonic system in the Sigma M30 employs a sophisticated micro processor controlled method of
detection. Unlike conventional ultrasonic detectors this method ensures that an actual entry has occurred
rather than just air movement, air pressure fluctuation, seat belt movement etc.
The detection system also employs a movement/time method where a certain amount of movement in a
given time is required to cause a trigger.
This method of detection offers a high level of protection against false alarms commonly associated with
other systems employing inferior methods of detection
In order to test the operation of the ultrasonics it is important to understand how they works when the system
is initially armed:
• For the first 16 seconds (settle time) the system allows the air movement inside the vehicle to stabilise.
(During this period the LED flashes dimly)
• During the next 16 seconds (threshold settle time) the microprocessor monitors the interior of the vehicle
- reducing the sensitivity (from the maximum sensitivity programmed by the installer, if necessary to suit
the interior and climate. (During this period the LED flashes brightly - latching on for a second only if
movement is detected and the sensitivity has been reduced)
• After the first 32 seconds the system is now fully armed and the ultrasonic sensitivity is set to the
programmed maximum or the reduced level if some movement was detected during the “threshold settle
time”.(LED now flashing dimly)
Because of the way the ultrasonics operate, if there is a disturbance within the “threshold settle time” the
ultrasonics will re-adjust to compensate for this disturbance, if the movement is excessive the ultrasonics
may turn themselves off. This re-adjustment can be detected by the dash mounted LED changing from
flashing, to a static state for a second. This may happen if the ultrasonics are tested in windy conditions with
a window open. If this is the case then the folowing test method can be performed:

Close all doors, bonnet and windows sitting yourself in the rear of the vehicle. Arm the alarm system keeping
very still, and observe the dash LED during the “settle time” and then the “theshold settle time”. The LED
must remain flashing and should not latch on. After these 2 periods the LED will then flash dimmly again,
moving your head forward now should trigger the alarm.

 

Wow, that really is impressive. A great bit of kit.