[Learner]

For those of us that do not have "OnStar" service:

Should you lock your keys in your car, don't fret. Call the person that has the second set of keys, ask them to press the "unlock door" button into the phone. Hold your cell phone close to the door so it will recieve the signal, and presto, the open will open.

I don't think it will work through a headset though.

[mrogers]

Huh? I assume this is an idea, not a real service, because I don't think phones can trasmit on the same RF freqencies as car key fobs. But, it is a great idea! Unforunately, it wouldn't work on many cars because more and more (like mine) change the RF code every time you put the key in the ignition to keep someone from using a scanner to read the signal and then try to get into your car later--it won't work because the code's been changed!

[dzervit]

Old, old urban legend. Search snopes.com and you'll see how ridiculous it is...

[PingGuy]

The RF frequencies that transmitter's use are far too high to be replicated by a speaker. It's possible that a future Blackberry could be built with an RF transmitter built in to do this function but highly unlikely that it would happen.

What would be more likely is that cars would eventually have bluetooth built into them and you could link your BB to you car as a trusted device and unlock it that way.

[mrogers]

PingGuy--

Phones DO have RF. If this were possible, it would expect it to be done through the phone's own RF transmitter, not the speaker. Furthermore, many cars do have bluetooth in them now (Acura TL and RL, BMW 3, 5, and 7 series, Lexus, to name a few), but there is no functionality like you speak of....that would be really cool, but it would require some serious security on BT, which is about as secure as swiss cheese right now.

[BBFreak]

It is true. It does work with SOME cellphones. I never tried it with my Balckberry, but it worked with my i88S phone and my i730 from Nextel. I was out of town, locked my keys in the car, called my wife (thought I would give it a try, I didn't believe the email I had gotten about it, but what the hay) and it worked. Tested it many times, sometime it worked, sometime it didn't.

[dzervit]

I gotta call BS. Your 800Mhz range i730 isn't even close to the 300mhz or so your car handles. Cell phones as a repeater for keyfobs... .owww, my ribs...

[BBFreak]

Contacted Autopage to find out why it worked: he told me it is possible. Contacted Onstar to see what input they would have, they said it could work also depending on model of car and location. My car does have Onstar but I didn't use it.

[PingGuy]

Originally Posted by mrogers

PingGuy--

Phones DO have RF. If this were possible, it would expect it to be done through the phone's own RF transmitter, not the speaker. Furthermore, many cars do have bluetooth in them now (Acura TL and RL, BMW 3, 5, and 7 series, Lexus, to name a few), but there is no functionality like you speak of....that would be really cool, but it would require some serious security on BT, which is about as secure as swiss cheese right now.

If I understand it correctly the RF transmitters in cellphones are only capable of transmitting on the frequencies of the network they are designed for. Furthermore for this to work the phone by the keyfob would have to have a frequency scanner running constantly and then would have to be programmed to forward the signal to the phone on the other end. Finally the phone on the other end would have to be capable of transmitting on the same freq as the keyfob.

I can't see manufacturer's putting this option into phones and not saying word one about it. Something like this is so frickin cool that you'd see commercials for it day and night if it existed. I am quite skeptical that it's been done before.

[Mark Rejhon]

OnStar is correct, on one condition

This would work -- but only in AUDIO rather than RF.

Much like an encrypted sequence of touchtones (an encrypted audio key, so to speak), to transmit an unlock code to a car... If the car has a microphone that listened to an audio "key", this could potentially be possible, even if the code was changed. Yes, even if the code changes every time - since the authentication would go two ways through the cellphone (headpiece and earpiece), allowing changeable codes to work. Yes, it could technhically be made to work. Yes, it would still be completely safe from recordings (i.e. taped recordings won't work) because the audio key is changed every use.

I would have to call BS on RF though...

But, yes, I say it is possible on audio frequencies transmittable through cellphones... Provided the car has a microphone instead of an antenna. It's definitely technically feasible and doable, assuming the codecs in the cellphones don't scramble up the "audio key" too much.

The question is, are those "working" cars really using audio instead of RF?
Remember, not all key fobs use RF!!! Some use infrared, some use sounds.

The ones that uses sounds, are the ones that will "work" over a cellphone. These are NOT RF.

The early key fobs used the same code.... Such as infrared, which was learnable by a programmable remote control. So that a thief could just use a remote control to unlock a car. A tape recorder would be an equivalent risk. However, if the key changes every use, then...

[Incognito]

Originally Posted by mrogers

Huh? I assume this is an idea, not a real service, because I don't think phones can trasmit on the same RF freqencies as car key fobs. But, it is a great idea! Unforunately, it wouldn't work on many cars because more and more (like mine) change the RF code every time you put the key in the ignition to keep someone from using a scanner to read the signal and then try to get into your car later--it won't work because the code's been changed!

If this is the case, and the RF code has been changed since you last started the car, wouldn't that theoretically (sp) make your SECOND remote useless? How would your SECOND remote know when to code hop with the original remote? Say you use your original remote 5 times, then used your SECOND remote to open your doors the 6th time U enter, how does the 2nd remote know what code to use now?

[rta53]

Originally Posted by dzervit

I gotta call BS. Your 800Mhz range i730 isn't even close to the 300mhz or so your car handles. Cell phones as a repeater for keyfobs... .owww, my ribs...

dzervit,

Where did you get that emoticon, I love it.

[dzervit]

I ripped it off of Yahoo! Messenger... just right click and save the image to have a copy of your very own!

[roofus]

I use a coat hangar!

[rta53]

I call Triple-A 8)