If you have an extended warranty, have the dealer replace the antenna/receiver, whatever. My bumper receiver didn't respond to my keyfob nor the trunk switch near the rear license plate and was replaced under extended warranty ('06 here)

Wish that I DID have the extended warranty. Unfortunately, I don't, which is why I am trying to chase this down myself. The dealer wants $80 before they'll even LOOK at the problem. And the first thing they said is the key fobs need to be "reprogrammed", even though they still work and sometimes the RKE system works like it is supposed to. Doesn't make any sense to reprogram, and I'll end up spending hundreds of dollars while the Dealer works through their troubleshooting decision chart.

I am now having this issue. The car won't arm or disarm from the handle button, and now I am having trouble turning the key since now I am getting a mixture of flashing red & green KEY lights. Batteries in the key card don't seem to be the issue.

Are we concluding that the sensor in the rear bumper is the culprit?

I've got the same problem recently and the mechanic told me its because of "interference" of other waves....

I don't think so.

Its the rear antenna the real culprit based on our experiences since we have quite a few in the car?

Thanks!

I can't help with this. Since I posted here, this issue had magically resolved itself for a couple of months. 2 months ago, it came back and I haven't done anything about it yet. I don't think it is specifically the rear sensor... Can your car detect the key is inside and allows you to turn on the engine? Or you can only use the key?

Great. After doing some research, looks like I have this problem...Ugh. Don't want to remove the bumper in below 0 weather......Wonder if I can reach from it, the opening by the license lights....Put a flash light in there, it looks fairly clean but the damn area is not sealed for sure....

Anyone have a pic of the antenna or at least a part no.? I can't seem to find it online at all.

I also couldn't find any info on the internet. But when I was taking out my tail lights, I noticed something that could be it. Take a look at the photos attached, MAYBE that is it?

I don't know if I mentioned it somewhere in this thread. My keyless entry problem went away by itself last winter, but returned last summer. I was hoping it'd fix itself again this winter, but so far no luck.

So, anyone made any progress with this?

I'm so glad I found this thread. I've been having intermittent issues with this for a while, but a couple months ago it became permanent. I brought it in to the dealer who wanted $430 to replace just the rear antenna. Unbelievable. When it warms up I'm going to remove the bumper and try the cleaning approach a couple people mentioned.

Otherwise, does anyone know where we could purchase this part if it is indeed faulty? I can't see paying the dealer $300 for just this antenna part.

The obvious choices would be the dealership and perhaps junk yard or eBay. But as this option is less common, finding the part could be difficult..

When you were talking to the dealership, did they give you a part number?

There is a part # in the picture....

I took the photos and I don't even know if that is the part. Are you saying that you are 100% sure that part in the photo is the trunk antenna?

The answer I got from www.onlinemazdaparts.com is that the part number is FE94-67-6N0B.

According to their website it can be purchased for less than $100. I'm going to try cleaning mine when the weather gets a little warmer, and will replace it if that doesn't do the trick.

RED KEY light on dash, keyless entry antenna location
 

I was wondering if you cleaned yours and what happened if after cleaning, it didn't work? I have the same issue. Red KEY in dash, my advanced keyless entry card works sometimes and then doesn't sometimes. I have replaced the battery in the credit card keyless remote. I also can not get the buttons on the door handles to work. No beep or anything. This is confusing. I am looking at the part # that was referenced aove. I still did not understand if this is actually the antenna previous people above are referring to. I have a 2007 Mazda RX8, Grand Touring 6 sp:sad:

Yes it is.

I haven't gotten around to it yet. I may give it a shot tomorrow afternoon since I have some free time. I was debating just buying the part so I wouldn't have to remove the bumper twice, but I think I'll try the cleaning method first and see if that fixes it.

It's sad, but I've gotten really used to just using the key buttons now instead of the keyless feature. It's been broken for close to a year.

*Update*

I took the bumper off this past weekend, which was kind of a pain in the ass. I found the antenna, took it off and cleaned it, but no dice. I ordered the new part, and it should arrive by the time I get back from my work trip. I'll get it installed early next week and let you folks know what happens.

One thing I did not think to try after cleaning the original was disconnecting and reconnecting the battery. Perhaps a reboot of some sort would make a difference? I'm not really sure how much of the keyless entry system passes through the computer.

**Update #2**

The part number I listed earlier (FE94-67-6N0B) is the interior rear antenna, the one in the trunk. Unfortunately that's not the one that's causing the problem on my car. I called the dealer and had them confirm that when they ran the code from my car it indicated that the problem was with the exterior rear antenna, the one behind the bumper. Now I have to figure out what the part number is on that so I can change my order. Good times.

I'm showing this as the part number your looking for, the one behind the bumper:


FE95-67-6N0C


Oh dang...it's expensive! Gotta love card keys!

Fixed! I ended up not needing a new antenna thankfully, because it is indeed an expensive part. I checked the antenna with a multimeter and it seemed to be fine. I cleaned up the contacts some more, and then disconnected the battery. Reconnected and voila! It's back up and running again.

I will probably give it one final cleaning and then put the bumper back on. The dealer wanted $450 to fix this, I did it with a $5 can of contact cleaner and some time.

RED KEY light on dash, keyless entry antenna location
 

I'm the happiest guy in the world today. I fixed my RED KEY problem & now everything works perfectly. Monday, I went to the Mazda dealer to see if they could figure it all out. After 3 hours of waiting in the customer care room, they came with bad news that it was the rear antenna gone bad as the codes said but after hearing what it would cost to replace it, I told them to forget it for now. To be clear, there is also an antenna in the trunk just under the trunk latch behind that plastic wall. it was not that one, but the one that goes up under the back bumper. I took the bumper off today & took all the connectors off, cleaned everything and put it back. Now everything works perfectly & didn't need anything but to be cleaned. I placed the antenna in my trunk area, just layed it in there as I don't wanna go back after it in that bumper again. I thought it might have a problem with it being there, but it does not & now I am just going to leave it in the trunk. Looks weird there, but after what I went through, who cares. I'm the only one that will see it when I open the trunk. Now I can walk up to my car & just use the outside request buttons to lock & unlock again, no more RED KEY!!:rolleyes:

RED KEY light on dash, keyless entry antenna location
 

Also worth a mention...my credit card key was not working like it was supposed to either. Sometimes it would unlock/lock the car & other times it would not. The distance from the car was horrible, I had to be right up on it for it to work, if it worked at all. I replaced the small battery in it, CR2025, and that did not fix the problem, so I thought it was tied in with this RED KEY mess. I decided to purchase another NEW battery 2 weeks later and it worked perfectly after the 2nd battery replacement in the card. I guess the first "new" battery I bought was dead from sitting in the store too long.

I have 2004 RX-8 base (sport) 6sp manual, simple remote key (no cards).

Remote start working every other time last few weeks and finally stopped working at all.
I went to Kragen to get battery replacement for remote, and noticed that they had that IR/RF remote key tester. According to that tester my remote signal was OK.

Sure enough with new battery remote still did't work :(

I'm wondering where to start.

Should I remove rear bumper or that only applicable for cars with credit card key?

Any advice appreciated!

I've got the same issue and question as you. Any help would be appreciated. Thanks!