This is probably more general to most Mazdas of this year, but I've just purchased a Mazda 5 year 2010 (quite love it) and the second key was in pieces with tape and all sorts, and i was told it was dropped. I cleaned it up and put it back together and replaced the battery. It will happily remotely unlock doors etc, but when i turn the key it won't start and the lock icon flashes on the dash. I'm assuming its not recognising the immobiliser? Is there an easy fix for this, or is it a new key time?

Thanks!

 

There should be a small "chip" in the top of the remote. It is very small and looks like a broken piece of plastic. I'm guessing when the remote was broken it read lost.

 

Thanks so much. So if this is the case, it's a new remote i guess?

 

Unfortunately, yes. I tried 3 from Amazon, none of them worked. I still need a third. I want to find a good used one.

 

Ah got it. So if I found a used one I could use my key and reprogram the used one I found?

Thanks for helping!

 

In the half of the head of the fob with the key, there's a black chip that basically looks like part of the structure of the key. If yours broke apart, the chip may have fallen out. Car won't start without the chip being in proximity to the ignition. Watch this guy's video here: (shows you the "immobilizer"). I believe you need two good keys (immobilizers) to program a third, otherwise you gotta go to a dealer or locksmith who has the programmer. You can program the fob transmitter yourself, though, with one good key.

 

Perfect! You are correct, it looks the immobiliser has fallen out at some point which explains exactly why it can't be started!

Thanks all, seems like a trip to Mazda is in order.