[audioholic]

I am not sure how the keys are paired to cars in the factory, but this seems like a case of two keys being paired to two cars, which is pretty bizarre. I had attempted a similar setup once when I had paired my WagonR remote with the SX4 and both cars could lock and unlock simultaneously. My SX4 came with a separate remote for keyless entry and the later ones came with the remote integrated into the keyfob. Hence, I wanted to change the remote to the integrated one and my WagonR had a similar setup. Hence, before ordering the blank remote and key I experimented pairing the remote of the WagonR with the SX4. Surprisingly, it worked, except for the issue that I had both my cars lock and unlock at the same time After the experiment proved to be successful, I reset the pairing by adding the SX4 remotes back which erased the pairing with the WagonR remote. Here is the process:

https://www.youtube.com/watch?v=Sm-ZzB3-3r4

Hope the above case has not happened with the Tiago. Newer cars are to be paired with the OBD tool, and maybe a visit to the ASC will solve the issue of the Tiagos, or it will require new remotes on one car, in case all the four remotes have similar identities which makes two cars recognize the same set of remotes.

[GTO]

Looks like Tata has seen this thread. Mayur says:

Finally, I have got an appointment at the Tata service centre for my remote locking issue and they have called the other car in too...this Saturday at 2 pm.

Tata has assured of assistance and rectification.

[Motard_Blr]

The lock and remote unit is supplied by Hella. They also supply to VW, among others. So it's possible that what happens in a Tata could very well happen to a VW too.

I agree that nothing beats a physical theft deterrent, such as a steering lock, for peace of mind.

[itsmb]

A friend of mine used to work for Minda around 15 years ago. I remember having a discussion with him about bike locks; According to him, they(Minda) used to supply one thousand key and lock combinations to each manufacturer per model. Which technically means every thousand+1 key is a repetition. He is presently working with Tata Motors and I have forwarded him the link of this thread, waiting for his response.

[Latheesh]

We had a 1995 Suzuki Shogun which we brothers use. One night my elder brother took it for going out for dinner with his friends. After the dinner he went to the parking lot, took the bike, and came back home. After parking at home he noticed something strange, bike looked very clean. We hardly wash our bike and on close inspection we realized that it was a different Shogun. By that time original owner of the bike had filed a police complaint and we had to take relative's help to resolve the matter. Parking area of the restaurant did not have proper lighting, and my brother by mistake took the other Shogun parked next to ours using our bike key.

[amitk26]

Originally Posted by Thad E Ginathom

I remember, back in the days of remoteless-entry...

A friend and I were going out one day. I asked him to start putting some things in my car ("The white fiesta outside") and gave him the key. When I went outside, I was puzzled to know where the bags were. Answer: in my neighbour's car! The same key unlocked both. In those days, car thieves knew they could access many cars with a relatively small collection of keys.

This is the first time I heard of it happening with remote locking, although there are known hacking methods of bypassing these locks.
.

If you have a metal 12 inch scale and/or a wire coat hanger you can open almost 90% of car using either of the two or a combination .

I feel most manufacturers keep door lock specification loose to deal with key left inside scenario so may be possible in ford you had.

[InControl]

A neighbor of mine bought a Suzuki Ciaz ZXI+, the problem is his key also unlocks the Brezza parked in opposite building. He has raised the issue with Maruti but they want him to bring both the cars at the same time. This has not happened yet and both of them are living with the issue since the last one year

[blackwasp]

Originally Posted by InControl

He has raised the issue with Maruti but they want him to bring both the cars at the same time.

Just adding some info. A customer of mine (when I used to work in a dealership) had got this done on purpose to unlock 2 of his Maruti cars at once so he could give just one key to the car washing guy to open both of them.

AFAIK, the remote will only unlock the car but if the car uses a RFID based immobiliser chip in the key fob which must be present in the car at all times to start the engine, the car simply won't start. One can only open the car and lock it. Similar functionality could be used for people using a garage door remote opening. Just program your car key to open the door instead of using another remote.

I'm guessing its something to do with the no. of different codes available that will be acceptable by the car. If this number is small, there could an accidental pairing from the factory itself. This seems rare as cost of electronics has gone down or the supplier is using less no. of bits. Generally a 40-bit code is used. Or the two cars were paired at the same time and got programmed to the same set of codes accidentally.

Cars with rolling codes will be even trickier to do so accidentally. Note than one can always program another key to the car (lost key, one more spare key, etc.). It's just that the probability of this happening randomly is too less.

Also I've heard this, but never tried: If anyone wants, press the lock/unlock button of your remote out of range from the car for 256 times. On the 257th attempt, it will forget the pairing with your car. Now go near the car and try using the remote and it won't work. You'll have to reprogram the remote to the car.

EDIT -

Originally Posted by GTO

Both our keys had the serial number '5016'.

Now that you have mentioned this, yes, I recollect that Maruti cars come with a 4 digit key number. Its mentioned on invoice as well incase the owner loses it. So every 10,000th car's remote will unlock you car?

[GTO]

Originally Posted by itsmb

I remember having a discussion with him about bike locks; According to him, they(Minda) used to supply one thousand key and lock combinations to each manufacturer per model. Which technically means every thousand+1 key is a repetition.

Originally Posted by Latheesh

After parking at home he noticed something strange, bike looked very clean. We hardly wash our bike and on close inspection we realized that it was a different Shogun.

My best friend Nick got a black Yamaha RX100. A year or so later, I bought one too. Reached Bombay Cycle & Motor Agency on his bike for the delivery. While I was signing on the documents, Nick was checking out my new motorcycle. He inserted his key into my bike's keyhole & voila - it powered up!! Both our keys had the serial number '5016'.

25 years later, if something happens where both of us think of or do the same thing, we look at each other and say '5016'.

[Vinodh_Gowda]

Originally Posted by GTO

Thanks to Dr. Mayur Nath Reddy for sending this in. Heartfelt gratitude for sharing it with other enthusiasts via this Team-BHP page! Dr. Reddy has written to Tata Motors and is awaiting a response. My concern is, are there any more Tiagos that the remote can unlock? Worse still, how many other remotes are out there that can unlock multiple cars?

Had shared the same in the official Tata Tiago review thread.
http://www.team-bhp.com/forum/offici...ml#post4393186

Now with the owner himself clarifying, seems like TATA is in big trouble.

[StreetAddict]

In my old office parking, locking my Swift using the remote would trigger a panic alarm of another swift. Too bad I was unable to locate the owner of that swift to do further testing.

Looks like the radio wavelength that locks my car was the one set to trigger the panic alarm of the other.

[Brumby]

I have a doubt here, was it just the indicators that flashed or the doors too got unlocked? We don't see the people opening the doors in the video.
I had a similar incident with my Innova (2008), where in the lights of my car flashed when another owner opened the locks of this car. I rushed to check and found that the doors hadn't unlocked and it was just the indicators that flashed. The incident happened in the parking lot of a shopping mall quite some time back.

[saur95]

From my limited knowledge of how this usually works, I understand that:

1. The remote (Called a transmitter) and the receiver are paired by the supplier - This is with an electronic code and will have 30+ bits or so. Unlikely to repeat.

2. The receiver is assembled to the vehicle by the car manufacturer.

3. Only the transponder in the key [Not the transmitter, unless its a jack-knife type where they are pretty close together] is paired to the vehicle by the manufacturer, and this is for allowing it to start the car - This is another long code. Will never repeat.


Now, a receiver can be paired with 'n' transmitters (Because multiple keys) and its probably a case of the supplier pairing one transmitter to two different receivers.

Its difficult for any manufacturer to track such a defect as they produce so many vehicles (The same key could be used for other models, which is the case here if I'm not wrong) and its just impractical.

The customer definitely deserves an explanation though and they'll probably have to unpair (If possible) or replace the key set along with receiver.

On a similar note, the chance of you being able to unlock a car with the key manually is higher. The number of permutations are limited because its mechanical (eg. 8-10 variables, each variable having 4-6 variations or so). Its just that nobody would ever find out because how common keyless entry is now.

[jassi_jeeper]

Originally Posted by InControl

A neighbor of mine bought a Suzuki Ciaz ZXI+, the problem is his key also unlocks the Brezza parked in opposite building.

I was being lazy and delaying my decision to buy a steering lock for my Ciaz. I will buy it today!
The gear lock is not feasible due to the AC ducting for the back seats.

[aniketi]

Has anybody seen this video before? This is scary .. Never ever keep your costly things in the car. Not sure if this works for all cars or not.

Edit - Video is not getting uploaded as its a mp4 file