I recently purchased a used 2005 Mazda3 S Sedan. Before purchasing, I had the car checked out by my mechanic and he noticed that the key fob wasn't working. When I returned to the dealer, they changed the battery and the key fob started functioning again.

A day later and the key fob's functionality was sporadic until finally...it just stopped.

I tried the steps suggested in the previous forums about reprogramming the key fobs, but no dice, they're still dead.

Two other things I noticed:
A) No matter if the key is in the ignition or not, as soon as the driver's door is opened, the car starts beeping. I'm not sure if this is just a normal feature of the Mazda3 or if it is actually abnormal. On my boyfriend's 2003 Mazda Protege, it only beeps if the driver's door is opened AND the key is in the ignition.

B) There's a flashing red light in the shape of a car with a key in the middle of the red car. It only goes away once the car is started. I'm not sure if that's supposed to be the anti-theft system or something else entirely.

Any help on the matter is GREATLY appreciated. Really, internet cookies (with binary chocolate chips!) to any and all help .

 

How could I pass up virtual chocolate chip cookies!!
Hi Ecnesse. Welcome to the club.

It does sound like something is not happy there and the ignition switch/beeping may just be the cause of most of your problems. If the key is in the ignition, the key fob does not work. Since you are getting the door chime even with the key out, which as you rightly guessed is incorrect, that's what I think is wrong there. The ignition switch "thinks" the key is still there when it's not. Try a little dry silicone spray. Use sparingly though, and run the key in and out a few times. See if that won't solve that problems for you.
Did you only get one fob with the car? There should be two. If it does turn out that you need a new one, they can be had pretty cheaply on eBay. Some seller offer a pair of them, while others sell them one at a time.

And yes, you guessed correctly about the little car icon too. That is the ignition disabler at work. If the wrong coded key is inserted, the disabler will not allow the car to be started for 15mins, IIRC.

 

I have some issue with silicone sprays and anything with electrical contacts, because silicone oils are good insulators and can mess up electrical contacts carrying low level logic type currents. For ignition switch assemblies, graphite spray is mechanically best, but is messy and does not de-oxidize corroded contacts. The overall best, and not at all messy, is electrical contact cleaner spray, because it cleans, de-oxidizes, and lubricates. Furthermore, you should apply it both to the ignition switch itself, and also you should open up the key fob, remove the battery, and give it a shot to. Key fob contact issues are usually battery contact related, but can also be caused by dirty function button contacts. If you still have problems, apply a couple of layers of masking tape to the inside of the fob cover to increase the contact pressure on the battery. Another trick is to try is to use the spare key, the everyday one may have just worn a bit too much.
But again, beware of using silicone based lubricants around low-voltage electrical contacts.

 

Thank you virgin1 and oldeng for your suggestions!

The dealer handed me 2 key fobs. However, neither worked. I'm not sure which key fob has been designated the spare since both were identical (at least to my inexperienced eyes).

I plan on buying 2 new batteries for the key fobs, since it couldn't hurt to completely rule out a dead battery problem (I know the dealer switched them out, but he might have given me dead ones to spite me). I'll be using the masking tape suggestion as well.

As for the electrical contact cleaner spray, where would I be able to find it? Would it be at a local Home Depot?

Thanks virgin1 for telling me about the coded key. The masking tape solution suggested by oldeng will be great for preventing a mix-up between my boyfriend's and my keys. I'm a notorious grinch getting out of bed and those 15mins would be crucial to getting me to work on time.

 

The masking tape is just a small patch of a few thicknesses attached to the underside of the fob casing opposite the battery location, it's just to give it a bit more contact pressure, and it is not visible from the outside; I guess you were thinking of wrapping a few turns around the whole thing.
The contact cleaner spray you can get from Radio Shack type of places who cater to hobbyists and aftermarket electronic stuff. It costs around $7.00 a can.

 

Virgin1 I think has got your problem about solved, if the car thinks the keys are still in the ignition, your car will not lock with the remote, period.

The beeping with no keys in the ignition is a sure sign that the car is confused.

Either try the contact spray in the ignition, or if it is still under warranty get it replaced.

 

I agree 100%. If the car keeps dinging with the key out, the key-in tumbler (or associated sticking relay contact) is the problem. For a brutal diagnosis, remove the key, open the driver' door, and if the car starts dinging at you, try beating the ignition lock severly with the handle of a large screwdriver to see if you can make it shut up. If this fails, do the same thing, but this time beat the crap out of every relay you can find on the firewall up under the dash on the driver's side.

 

Sometimes with the door open, if you depress the key opening in the ignition with your finger it will beep.

See if that may be stuck.

 

All I want to know now is where are my Ch.Ch. cookies?

 

+1 to what virgin1 said. AFAIK it's not that there's something stuck as much as it's actually broken. In the past people who've had this problem have had to have the ignition tumbler replaced.