[navin]

Originally Posted by mjothi

My Zen had a remote lock (Perana).

If one removed the rear glass in he zen (it is possible and very doable if onehas 2 screwdrivers to stick under the rubber beading) one can enter the car and unlock it.

[amitoj]

Originally Posted by Sam Kapasi

Sir, an audio signal is merely the final user interface, so that the user can comprehend the data being transferred. Audio signals cannot be relayed on-air. Any phone (even cordless), on any end does not send or recieve audio signals.

I am not a telecom engineer so I cannot elaborate as much as I'd like to.

I am not agreeing with the poster, I do not know if it is possible. I am merely saying that it is not impossible that the unlocking signal frequency somehow piggy backs on the carrier signal.

LOL. Sam it seems you understood just the first line of my post and hence have commented only on that. The main point of my post started after the first line actually.

I agree with you that if the alarm is being unlocked by the cellphone then its due to the RF signal the phone is getting, and not due to the sound the cellphone near the car is producing or the one near the duplicate key is getting.

My point is that the signal for the car alarm is supposed to be encrypted (secured) which is not supposed to be replicable by any other transmitter. If a cellphone is unlocking a car, then definitely the security system is weak.

A silly question for those who are saying that they have seen it work. Are you guys sure the car was out of range of the duplicate key?

[DirtyHarry]

Originally Posted by tsk1979

A phone speaker produces audio frequencies.
If your central locking system is unlocked by audio frequencies, then I suggest you get a new security system, lest your car unlocks every time somebody farts

My apologies for not communicating effectively. I was only replying to the post that "it works through mobile phones" - my post was supposed to communicate that it does NOT work.

I'm not sure where the “fart” come into existence but as a new entrant I see that moderator’s post is full of stench.

Note from mod: Please do not use [COLOR] tags, they do not work and make post reading difficult

[tsk1979]

Originally Posted by DirtyHarry

My apologies for not communicating effectively. I was only replying to the post that "it works through mobile phones" - my post was supposed to communicate that it does NOT work.

I never replied to you buddy. Just because your post is above mine, does not mean I am replying to you. I was just talking generally about this idea(which does not work, the physics of which I will not go into right now).

I'm not sure where the “fart” come into existence but as a new entrant I see that moderator’s post is full of stench.

I apologize for this, Yesterday I went to coffee day and had something with whipped cream. The whipped cream was old, and since morning I have been "stenchy".

As for this topic.
What happens in a mobile phone conversation.
you speak into the speaker. The speaker picks up "audio signals"
They are modulated onto GSM or CDMA, and relayed by the cell tower etc., etc., to the handset of the person you are speaking to, where they are demodulated into sound again.

Now if a cell phone could pick up all RF, then if you shone a torch at your cell phone speaker, the guy whom you are speaking to would have gotten light out of the earpiece.

Moreover when you speak, there is signal loss(noise etc.,),
In case of such precision security signals replication using a audio speaker will not be possible.
for example try this(for the audiophiles),
1. Generate a 400KHz audio signal. You won't hear it, but you can use a detector instrument which will detect it
2. Do the same, but now in front of your cell phone, with another cellphone and detector far away. The instrument will not detect anything, because your audio speaker has a limited frequency response.

[DirtyHarry]

Originally Posted by tsk1979

I never replied to you buddy. Just because your post is above mine, does not mean I am replying to you. I was just talking generally about this idea(which does not work, the physics of which I will not go into right now).


I apologize for this, Yesterday I went to coffee day and had something with whipped cream. The whipped cream was old, and since morning I have been "stenchy".

As for this topic.
What happens in a mobile phone conversation.
you speak into the speaker. The speaker picks up "audio signals"
They are modulated onto GSM or CDMA, and relayed by the cell tower etc., etc., to the handset of the person you are speaking to, where they are demodulated into sound again.

Now if a cell phone could pick up all RF, then if you shone a torch at your cell phone speaker, the guy whom you are speaking to would have gotten light out of the earpiece.

Moreover when you speak, there is signal loss(noise etc.,),
In case of such precision security signals replication using a audio speaker will not be possible.
for example try this(for the audiophiles),
1. Generate a 400KHz audio signal. You won't hear it, but you can use a detector instrument which will detect it
2. Do the same, but now in front of your cell phone, with another cellphone and detector far away. The instrument will not detect anything, because your audio speaker has a limited frequency response.

Thanks for the explanation. I am in agreement on the same lines from the begining that it is NOT possible to unlock a car through a mobile phone. Somewhere this is being missed out.

I guess the coffee shop people must be busy fumigating various rapscallion creatures that want to drink their coffee before the homo sapiens. Good luck with your tummy.

Note from the Support Staff: Please do NOT use text format tags. Thank you.

[alto99]

The mobile thingy seems scary.
If that is indeed possible, I would then say the security systems are unreliable as it would be possible to record the signals and reproduce them to unlock cars. So beware as someone might be recording these signals while you are unlocking your car! Use your key instead....
And are car thieves sleeping?

[mjothi]

To people who "felt" this will NOT work,
I cannot go into techie aspects of this since I dont know ABC of these stuffs. I remember reading it and got convinced when I read that old article. Anyway, atleast in my case, i had the result and without any "harm" to my Zen, got in just by implementing it. Some sort of Telepathy

Also, you can try it out as I think no harm in trying this. Ofcourse I cant guarantee that it works in all permutation and combination...
Probably in next meet, lets have a demo sesion

Btw, I was in Annanagar Popular show room and the other Duplicate was used from more than 10km away. I am sure the remote doesnt have such long proximity to work from that distance.

[prabuddhadg]

Originally Posted by alto99

And are car thieves sleeping?

No, they are probably surfing through the Team bhp threads for more info.

[diabloo]

What about cars like NHC, where the central locking is silent?

Originally Posted by alto99

If that is indeed possible, I would then say the security systems are unreliable as it would be possible to record the signals and reproduce them to unlock cars.

[revvedup]

I remember seeing a TV show by the name of Auto Motor and Sport where they showed how every car right up to a Porsche 911 can be stopped from being locked via the remote by simply using a Walkie-Talkie set at an apppropiate frequency that could intercept the signal from the remote. Can someone explain how this is possible ?
Edit-found this using Google Use of Walkie-Talkies to Steal Cars [Archive] - Philippine Macintosh Users Group

[jayguar]

I have done it a couple of times in my previous car, the Santro. This happended a few years back. The first time, I was just getting out of the car and accidentaly pressed the central lock and closed the door with the key inside. Since it was near my home, I was able to get the spare key. The second time was a nightmare. I got out of the car to meet a friend with the engine running and locked the car accidentaly. I really had a tough time to open. Finally I had to remove the rear quarter glass, open the rear door and then the front door. When I went to the service center, the guy there told me, that I should just have removed the beading in the front window and use a rod to open. Now I am lucky. I cannot close any of my Honda cars without a key. Technology surely helps me here.

[greenhorn]

Me and a friend went for a long drive. We stopped to eat. Halfway while eating , it occured to me that I'd forgotten to lock the door on my side. Was agonizing over how to tell him this ( the area we parked wasnt exactly safe). I didnt relish the thought of us getting stranded sans car in the middle of nowhere .

We ate , and we ate some more. I wanted to finish the damn meal, and run back to check if the car was still there. Towards the end, I could suffer it no more. Asked my friend to get out. That I'd left ,my phone in the car , and wanted to get it.

Then he sheepishly admitted that he'd locked the key inside the car. For a moment , I didnt know what to say

Then i sheepishly admitted that I'd forgotten to lock the door, and we had a hearty laugh , and were on our way !

Thats the first time two wrongs ever made a right

[praveen_v]

From this thread, I came to the conclusion that unlocking cars without keys is pretty easy. So I guess manufacturers can now stop using keys for locking doors and use them for ignition alone

[Sam Kapasi]

Originally Posted by diabloo

What about cars like NHC, where the central locking is silent?

My friend when he says record, he is not referring to the silly hooter that makes beep beep when you lock. He is referring to the capture of a radio frequency that is transmitted by your remote and received by your car.

[psp62in]

Guys, On the subject of unlocking through the mobile, there are plenty of discussions on the web to confirm that it is a HOAX. I am just giving one below for those interstsed in the details,
Unlock Your Car With Your Cell Phone? - BreakTheChain.org