[300DFan]

When I bought my car a few years ago one of my key Fobs was a little flakey.

It would seem to work fine, then occasionally the remote would simply not lock or unlock the car. And when I put the key in the ignition the car wouldn't recognize it. But if I removed the key and tried again the car would start and the remote would magically start working again. I fiddled with it some and tried new batteries but nothing seemed to have any effect.

I concluded there was something wrong with the key and simply used the other one, which seemed to work flawlessly. Until recently.

Now I have two keys with the same intermittent failure symptoms. How likely is that? Is that a common failure mode for these keys? If I just go get a new key from the dealer will it likely work, or should I suspect some problem in the car that is now affecting both keys?

 

[rudeney]

Since it;s now bot keys, it could be the antenna amp.

 

[300DFan]

I was afraid of that - but that wouldn't affect using the key in the ignition, would it? I thought that was unrelated, and even if the remote function of the key or the amp failed the key should still work normally in the ignition. But I now have two keys that also intermittently fail in the ignition. So far they always seem to work on the second try in the ignition but I'm not confident they will continue to. It seems to be a weird failure mode.

 

[rudeney]

Oh, sorry I didn't read the part about them not working in the ignition. In that case, I'd guess it's a problem with the EIS, but it could coincidentally be two keys with failing circuit boards.

 

[300DFan]

Since my radio reception is good and I also have the intermittent ignition issue I think I'll rule out the antenna amp. It has to be either an EIS/CANBUS issue or two failing keys.

I remembered that I actually have a third key, which is not a remote - just a simple plastic shell with no buttons or battery but it can be used in an emergency with the metal key to get into the car. I've decided to use it in the ignition for a while to see if the car ever fails to recognize it - and so far it's never failed.

If the emergency key continues to work consistently in the ignition I'll conclude both key fobs are failing and get a new one. If the car ever fails to recognize this third key I guess it will be a trip to the dealer for a new EIS ($$$).

 

[93SoCal400E]

The Smart Keys can be repaired, especially if you can see a small hairline crack or broken piece.

It is also relatively easy to move the flash chip into a good key. If you know someone with a hot air reflow station all you would need would be some used keys from Ebay.

I was able transfer both of my plastic keys into Metal fobs. Would be a lot less money then buying new keys from dealer.

 

[300DFan]

If the emergency key continues to work consistently in the ignition I'll conclude both key fobs are failing and get a new one. If the car ever fails to recognize this third key I guess it will be a trip to the dealer for a new EIS ($$$).

Just to follow up on this I decided to get a new key from the dealer and it works fine. So I did in fact have two key fobs that were intermittently failing.

I guess 14 years is a reasonable life expectancy for these but replacements sure aren't cheap if you aren't inclined to try soldering these tiny components. At least I now have one of the shiny new chrome ones.

 

[93SoCal400E]

If you didn't through them out or have the dealer remove them from the car database, they can be fixed

Or even moved into Chrome housings. (provided you aren't on Keyless-Go)