Key fob battery

[saleen836]

Ok, if I lock an '07 mx5 using the remote key fob and the fob battery goes flat how do I unlock it with the key without the alarm going off?

Yes I know it sounds daft but I'm guessing there is a simple solution? (hopefully)

[MX-5 Lazza]

Surely using the key won't set the alarm off. I've never had a car where the key didn't work exactly the same as the remote - assuming it's not an aftermarket alarm system.

[Craikeybaby]

MX-5 Lazza said:

Surely using the key won't set the alarm off.

It will! It happened to me on my 2011 car, luckily my girlfriend wasn't too far away with the spare key, so we were able to silence the alarm with that. The funny thing is I'm sure that the fob hadn't worked before and I'd unlocked with the key without any problem. One thing that I didn't think to check was if starting the engine would stop it.

I don't know if Mazda replace the batteries in the fobs at service, I'm guessing they don't, so for the sake of a couple of quid it might be worth replacing them every year.

[MX-5 Lazza]

Maybe it's different on Mk3 then (though I don't know why they would make a backward step like that). I'm pretty sure I can unlock my 2001 Mk2.5 with the key without it setting the (factory) alarm off.

[Craikeybaby]

It probably isn't a conscious change that Mazda used, probably more something to do with a chip/locking ECU change.

[sbird]

The battery in one of my keys went flat. Swapped to the other key then bought a 10 pack of batteries from ebay for under a fiver. Well worth having a spare. Probably worth leaving one of the spares in the car boot.

[Superhoop]

Thatcham don't like alarms that are deativated by a micro-switch in the back of the lock barrel in the door, as the alarm can easily be defeated by forcing the lock with a screwdriver, so whilst the MKII does deactivate the alarm, from the MK3 onwards, it doesn't.

Starting the car with a valid key overides the alarm though