The Incredible Hulk

Over the last 6 months my standard subaru car alarm installation (01 WRX) has decided intermittently that it wouldn't open the car, or close it using the remote. Well today after having to manually open the car in Bristol City centre with the alarm screaming for all it was worth I called my dealer. He advised me that this was not unknown and the mobile telephone masts, etc caused the alarms to throw a wobbly. Have any of you come across this before - the service manager was as good as gold and will order the 'upgrade' from sigma to be fitted under my warranty.

Kevin

Apple

I think if you have a search, there's quite a few posts regarding sigma alarms throwing a wobbler whilst near masts - it happened on earlier versions and there's been a tweak done on the later ones to sort it... AFAIR it's something to do with the frequencies they use and the power levels involved which can be swamped by a relatively massive signal from a mast...

There's an explanantion by Sigma Sam on a fairly recent thread that goes into a lot more detail.

Andy

The Incredible Hulk

Thanks Andy, I will have a quick search.

Kevin

Sigma Sam

just incase.........

Radio Lock Out
- All alarm systems manufactured for use in the UK in ’99 were required to operate on the frequency of 433MHz. Subsequently, in late 2000, the government allowed the introduction of the “Tetra” radio network for telecommunications companies, the military, police, fire and ambulance services etc, which was allocated the 420-430MHz bandwidths.
Although not exactly the same frequency, these “Tetra” transmitters are licensed and so are allowed to operate at around 20,000 watts, compared with the alarm systems 0.5 watt radio key (necessary so that your radio keys remain exempt from annual licensing fees!)
As a result, when you are near a transmitting “Tetra” mast you can get a degree of “bleed over” as their signal is so much stronger and this can swamp the transmission from the radio key. This problem is not exclusive to this system and can occur on any number of manufacturers systems produced prior to 2001.
The receiver boards were redesigned to focus more accurately on the 433.92HHz frequency as soon as this problem became evident, however, systems manufactured before 2001, with the older receiver boards, are not faulty and were NOT considered eligible for warranty, although as a goodwill measure, customers who suffered from “exceptional” radio lock-out (ie lived or worked below a mast) were offered an upgraded receiver board if the vehicle was still within the warranty period.

This goodwill period was extended for a further 12 months after the 3 year warranty period expired, but ended in December 2004. The later ECUs are still available from Subaru (part number SACC 3465) but these are now chargeable.



Avoidance.
There are a few points that should be remembered:
- All vehicles that passed through the import centre from January 2001 are equipped with the latest receiver boards that are "Tetra Resistant" and so should not experience this problem.

- A keypad is fitted to ALL models with the UK standard fit alarm system (from 99 MY) as an emergency override, in the event of loss, damage, flat radio key battery etc. (The keypad also allows the driver to access a number of features and is a complete programming tool for the dealers) and so pushing/recovery of vehicle’s should not be necessary provided you know your override PIN and ow to operate the keypad.

- The keypad can NOT be affected by "Radio Lock-Out", as it is hard wired into the system and does not rely on a radio transmission.

- The keypad allows only THREE PIN attempts and then will "Lock Up" if an incorrect number is entered a third time. This is a secuity feature to prevent random attempts at steeling the vehicle, however, it is also an inconvenience if you are suffering "Radio Lock Out" and enter your PIN incorrectly.

- The PIN number should not be entered too quickly or too slowly - when a digit has been pressed the small LED built into the keypad will illuminate briefly as confirmation and only then should the next digit be entered.
If an incorrect digit is pressed or the delay between entering digits exceeds10 seconds, then the LED above the keypad will flash rapidly and the PIN attempt should be aborted and started again after 30 seconds.
Due to the small size of the keypad some users may find a rubber tipped pencil easier to use. DO NOT use the sharp tip of a ball point pen etc, or press excessively hard on the keypad as this will only damage the membrane and cause a digit to remain pressed, causing a continual incorrect PIN.

My advice is to read the alarm system's instruction manual and practice entering the PIN before you need it. If you do not know your PIN, or bought the car second hand (in which case the PIN may have been changed by the previous owner) you can change the PIN to one of your own choosing, using the keypad, provided that you have a working Radio Key.

To do this, following the alarm systems Operating Instructions - if you do not have these a copy is available at:

http://www.subaru-impreza.org/subarutalk/viewtopic.php?t=2476


Ensure your keypad is operational before you need it on a dark night!
I hope this has cleared up a number of points that have been raised and will help to keep everyone mobile.
SS

The Incredible Hulk

Sam,

Many thanks for the quick reminder. Hopefully this warranty changeover will see then end of that problem.

Kevin