Do you think it's possible that my Bluetooth cellphone is interfering with my Smart Entry & Start remote? Lately (oddly enough, just lately) I've noticed that when they're in the same pocket, often the car won't unlock and it'll also say there's no key present when I try to turn the car on. I have to remove the key, and then it works. Why would this be happening?

 

It could be possible for them to interfere. Any idea what the frequency range of the two is?

 

No idea.

 

Both your cell phone and smart key are transmitting using Bluetooth at all times, but is incredibly unlikely they are interfering....

Bluetooth communicates at a frequency of 2.4GHz. This is the same frequnecy as baby monitors, some cordless phones, and 802.11 wireless internet. In order to avoid interference, Bluetooth uses frequency hoping. Each bluetooth device has 1 MHz of bandwidth for transmission, and that 1 MHz jumps around the 2.4GHz band 1600 times per second. There are 79 different frequency positions. This hoping is pseudo-random. If two devices are sharing the same frequency, it will only be for 625 micro-seconds.

What does all this mean? It means that if your cell phone and your smart key happened to transmit on the same frequency, it would be for less than 1/1000 second. The two devices would then move to different frequencies.

I would check the battery on your smart key, and also see if there are other things can could be interfering, such as 802.11 networks, baby monitors, cordless phones, etc.

I hope this helps!

 

Yarok,
I've used both smart entry remotes, so it isn't the battery. Could it perhaps be simply the two metal objects being in the same pocket? The second I take the remote out, it works.

 

I'd say that's possible. Perhaps some radiation from your cell phone battery is causing interference. I guess the moral of the story is to put your cell phone in your other pocket

 

Well, I'm no electronics expert but I did manage to struggle through all 320 some odd pages of the manual and I do recall there being a specific part about other electronic devices interfering with SmartKey. Now, I would tend to discount this as one of the omni-present warnings one tends to find in such manuals except, just last night I noticed a problem with my SmartKey. I usually keep it in the same pocket of my briefcase and never take it out. But last the car didn't seem to recognize it.

Today, it's fine.

So what might have been the problem?

The only thing I can guess is that it happened to be, for the first time since I got the car, stuffed into the same pocket as the rest of my keys, on which hangs a transmitter for my remote start/alarm, for my wife's Jeep Liberty.

I don't know if they transmit at the same frequency but I do know that the key fob for the remote start/alarm sends updates (about every ten seconds) to the vehicle to check its' status. It's a two-way alarm with a display screen.

Given that, admittedly singular and anecdotal incident, and the text of the manual, I might infer that SmartKey is sensitive to interference.

I'd love to hear from someone more technically inclined.

 

That happened with my iPod in the same pocket as the key fob. Its probably interference in the 400Mhz range, which I recently heard that the iPod has a processor that was clocked around 400Mhz. It basically blocks the tranponder's frequency.

 

The manual clearly states not to keep the fob near any electronic devices. It may not work temporarily - and worse - the battery in your fob will wear down when you are NOT near/in your car. (Fob tries to "respond" to bogus signals.)