how do you start/disable alarm on elantra with no fob, only the key?
 

i have a 2003 hyundai elantra..well, had..just sold it to my daughter in another city for her first car..we lost one of the fobs for it, and a new one costs 150 bucks..sure enough, her mom (my ex) goes to open/start it with the key today after daughter used the fob last to lock it up..alarm goes off, she can't disable/can't start it. there MUST be some workaround for this surely as we don't want to buy another fob at 150 bucks..and my 16 year old daughter is likely to lose at least a fob at some point! ps- i believe that if it's last locked using the key rather than remote fob, it can be open/started using the key? but, that's a pretty imperfect system if that's the only way to do it. thanks for any advice.

See page 1-5 of the owner's manual. To disable the alarm without a fob, insert the key in the ignition lock and turn it to the "on" position. After ~30 seconds, the alarm will be disabled. I think on this vintage, the alarm will go off no matter how the door is locked if the alarm is not first disabled with a fob. Unfortunately, I think there is no elegant way to keep the alarm from triggering.

Hmm, I take that back. The manual says the alarm can only be re-armed with the fob, so might be able to lock/unlock the car with a key once the alarm is disabled.

Re: how do you start/disable alarm on elantra with no fob, only the key?
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Hi - I'm fresh off a tussle with this one, myself.

A quickie on my problem...
Have a 2005 Elantra, and it came with 2x remote fobs. Everything was going well until about the 3rd year in; while the remote would lock the car fine, the unlock cycle was very spotty (low hit rate to unlock). The first time I mentioned this to my dealer, they checked/reprogrammed/re-batteried my fobs, and they worked (for another couple of months) until a couple of months ago. And we were back to a lower and lower unlock hit-rate.

Finally, it all came to a head when the Elantra locked itself (something it would do from time to time, but always the fob would unlock it before...), and would not unlock at all with the remote!
I opened the door with the key, and of course the alarm screamed and then cut off after the requisite time. But the key in the ignition switch would not start the car, no matter how long it stayed in/switch was on.

So, I took it to my dealer (managed to start it by pulling the negative post off the battery, and 'cycling' the remote), and what the dealer told me (and this works...) is to keep all the remotes away from the car, and only use the key itself to lock/unlock the car. If one works it that way, you can always get in and start the car, if you've locked it with the key - and not the remote.
*But*, it's important to lock the car w/ the key when you leave it, as sometimes (as mine did) it will lock itself (noting that, if the remote is used to lock/car locks itself, then the immobiliser is engaged, and the key didn't override the immobiliser in mine - and the dealer couldn't tell me why that was...).
After two days with the dealer, the solution, it seems, is to only use the key itself to lock/unlock the car, and it will start, no problem. It is, however, a good idea to keep one working remote in a safe place (away from the car, and probably wrapped in lead sheet or something...the dealer advised me to keep the remote somewhere else than in the car....), and only use the remote if the car locks itself, like had happened to mine. So far, this approach has been working.
So, mate - deep-six the remote fob, and just use the key to lock/unlock; the central locking is unaffected and still works, inside and out.
NB - I never did like remote locking, anyway! And, you're right - the remotes can be easy to lose/damage if they aren't kept in a key folder or something. Just say no - to the remote fob... and use the key like the old days.

I have an 02 Elantra & choose not to use the alarm. I only use the key to lock/unlock & the alarm is unused.It is only active if you arm it. open it with the fob & dont use it to lock it again & no alarm! I have only one fob & cant justify the purchase of a 2nd(quoted at a dealer for about $60.00+programing) but I do know that you can buy one on ebay/amazon & program it yourself using youtube.