I have the same problem, and it definately wasn't there before. The Mazda manual says its supposed to come on and flash every 2secs after switching from ON to ACC and off again when switched to ON and whilst running.
It wasn't clear as to what happens when its in the off position but in my case there was no flashing 'key light' when in the Off position until now. Which indicates i have a problem, although noalarm or running problems have appeared.
Assuming you guys have the same light in the Mz6 that Richard and I have in our 3's (little red car with a key in it) it's the indicator light for the engine immobilizer and it flashes whenever the key isn't in the ACC/ON positions to let you know it's working.
I don't know why your alarm would be flipping out though.
In my '04 6S wagon, the security light ALWAYS flashes while the car is off. It does not flash when the car is on and running. So in that respect, it sounds like your car is behaving normally. I cannot explain why your alarm is going off, though. Try making sure the car is unlocked BEFORE turning off the engine, and see if the issue goes away. Please report back and let us know what you find out! Cheers,
David Teachey - '04 Mazda6 S Wagon V6 Automatic
Charlotte, NC, USA, Earth
My 06 6s does not have an alarm. I don't think the blinking red light has anything to do with the status of the immobilizer. The service guy says it's just a faux alarm indicatorto tell the would-be-thief to pick another car. It's just there to make the car appear tohave a real alarm likea Audi, BMW & Porsche.
For a car withan alarm,opening the door with or without akey(thief) before disarmingby using the remotewill always set it off.
My 06 6s does not have an alarm. I don't think the blinking red light has anything to do with the status of the immobilizer.
On the 3 the light is specifically for the immobilizer. It flashes a little red car icon that has a key in it. If you insert a key that either doesn't have a chip, or is not programmed then the light flashes really quickly.
I have a 2000 mpv. just replaced the ecm and now need to program it but the little security light on the dash isn't coming on at all? Have read on several other posts that the immobilizer and ecm kind of act as one so if one is replaced the other needs to be as well. Anyone know of any other reasons why the security light wouldn't come on? hate to buy a new immobilizer if not needed.