The symptom: Occasionally this winter, with the Mazda 3, I put the key in the ignition turn the key, all the lights in the dash come on, the fuel pump cycles, but the engine does not turn over. Turn the key to the off position. Turn the key again and usually ( though not always,) engine turns over and the car starts. Very disconcerting at first, but after a few times, I stop panicking. This happened to me at least a dozen times this winter in the 3. I took the car into the dealership for a faulty SRS sensor and mentioned it to the service manager. I left him the key, told him it was intermittent but he said he would look. No joy, could not reproduce the behavior Then, this spring, the same thing happened to me in the 8.

The nickel dropped right away. I have both the key for the 8 and the key for the 3 on the same key ring. If I hold the keys just so, both keys are too close to the detector and the detector gets confused (or enters a race condition) and does not recognize the chip of the key in the ignition as being the correct one. I was able to demonstrate this to my wife (also a software manager) and she commented that obviously the requirements for the ECU programming did not consider that two Mazda keys may be in close proximity to the detector. I will check if this bug is fixed in the next version of the flash….

 

That will never be fixed with a reflash. It's just the way the immobilizer system is designed. By having two Mazda coded keys in the vicinity of the sensor, you're confusing it and causing to believe theft is taking place. That's the whole point of having an immobilzer, to be discriminent to other coded devices or keys.

 

Bug?

This problem would be so rare I doubt it would be considered an issue at Mz.

The same system that protects both of your cars is what you are complaining about.

 

I think this is acutally also mentioned in the manual, that if you have other coded keys on the keyring (or large metal objects) it may interfere with the immobilizer functioning.

 

lol, so mazda never considered that someone might actually buy two of their cars? Interesting phenomenon.

 

I would submit that the end user requirement – being able to start the car – overrides system implementation simplifying assumptions – Assume only one Mazda key on a key ring. Just because someone knowingly or unknowingly made this tradeoff of simplicity over functionality doesn’t mean it’s not a system bug.

The fact that the car is immobilized doesn’t mean the immobilization system is working. It is necessary that the system do what it is supposed to do (allow the car to start in the presence of the correct key). Just because someone interpreted that as “and don’t allow the car to start if an invalid key is in close proximity” does not mean that the systems primary requirement has been overridden.

Having said all this, I agree that unless more people start owning/driving multiple Mazda offerings on a regular basis, the problem will not get fixed. And I can live with that.

 

I'd consider this a problem. Not a huge one, but if you haven't figured it out yourself, then it would have been a real PITA.

I mean, how many other electronic devices that have millions of possible codes do you know of that won't open if you have 2 of them beside each other. The electronic chip in one key should be different from another (even if the codes are close) and as long as the correct key is in the vicinity of the sensor then the car should start and there should be no confusion.

But good observation and recognition on your part pot8r!

 

I describe this here:
https://www.rx8club.com/showpost.php...7&postcount=16