Smartkey sometimes does not work

[ZoomFive]

Anyone have problems with their smartkey when they have it in the same pocket as their cellphone? As I am driving, my car will beep and flash KEY, as if I walked away with the key with the car running. This is a consistent and repeatable behavior.

Also...
My smartkey also does not work sometimes when I am parked in a certain spot at work about 50 yards from a microwave tower. Proximity does not work and pressing the unlock button on the smartkey does not work. I end up walking around the car pressing the unlock on the key until it is recognized.

At all other times, it is flawless.

Any similar experiences?

 

[CX9 SportOwner]

That's why the manual specifically tells you not to place the key next to other transceiver devices. RF interference.

 

[ceric]

ZoomFive,
I have a Prius with SmaryKey since 2005, now another one on CX9.
Those problems you described are "normal" EM interferences.
The problems are well-known.
Put your cell phone in a separate pocket should suffice.
As for Microwave tower... Don't park there?

 

[ZoomFive]

Yup, I usually put my key in the other pocket anyhow. The spot at work is the best place to park in that it is in the shade and is a parallel park space. The landlord decided to repaint all the head-in spaces one weekend taking about 10-15 from each space. Usually, people now can't open doors without bumping the car next to them.

 

[Lindyrect]

I have problems with my smart key not working even if it is in the other pocket. I have the auto lock feature. Sometimes it won't auto lock so I open the door again and close it getting no love. Took the FOB out of my pocket and hit close, nada. Hit it 3 more times, opened the door and hit lock again and the car finally decided to wake up. It does this once and a while parked in different places even with a brand new FOB battery installed.

 

[CX9 SportOwner]

Are you wearing one of those goofy headsets when you do that?

 

[Lindyrect]

Which kind, like the 80's walkman headsets? I only wear them when I speed walk and do pilates.

 

[CX9 SportOwner]

The Bluetooth headsets that people wear to look important.

 

[ceric]

Here is a essentially how PKE (passive keyless entry, a.k.a. SmartKey system) works.
"The Base Station starts the RF communication by sending out a 125Khz signal. The Key Fob receives and decodes the Low Frequency challenge from the Base Station. If there is a match, the Key Fob will transmit a 432Mhz signal back to the Receiver/Decode. If the Receiver/Decode recognizes the Key Fob as a valid device it will send out asignal to unlock the door."

As you can see, the SmartKey uses 125K and 432Mhz, while the BT uses 2.4Ghz open frequency (such 2.4G cordless phone). Basically, they should not interfere each other. Cell phones (depending on which band) operates on 1.7G-2.2Ghz.

That said, EM waves bounce around and can creates secondary harmonics, which can interfere with other bandwidth. Especially the 125K signal is designed to operate within 1.5m (low power). It can be easily over-shadowed by stronger interference.

 

[CX9 SportOwner]

it's the low power call out that is most likely being obscured. When you get that low, almost any strong signal, even HT power lines, can cause interference.

None of the transmissions are very powerful, anyway, to prevent someone from capturing your codes from a distance. They basically have to sit next to you.

 

[ceric]

PKE signals are encryted and code-rolling. It is not that easy even if a thief is next to you (such as sitting in the car parked next to yours).

 

[hamproof]

All I know is if I keep the smartkey front/back of my iPhone in my front pants pocket, I can't unlock the door.

So, the arrangement is, wallet on the right, phone on the left and smartkey on the back pocket. Hopefully it won't break when I sit on my fat ass.

 

[CX9 SportOwner]

PKE signals are encryted and code-rolling. It is not that easy even if a thief is next to you (such as sitting in the car parked next to yours).

Not to burst your bubble, but most keyless entry systems only use a 40 bit encryption, allowing any laptop with a transceiver and the proper software to handshake with your key and capture your RFID codes. Then they go to the car, send the code, and they are in.
128 Bit chips are starting to be used, but very slowly.

If you are in a Starbucks, and some stranger with a laptop chats you up, they may be stalling you to get your key codes. The good news is that they do have to be very close to get it, but it can be done, and the decryption rarely takes more than 15 minutes.

 

[ceric]

How about code-rolling?
I think you covered the encryption part, and I agree, with proper software, the encryption can be cracked. However, code-hopping + KEELOQ makes it very difficult. You can't find that on your typical keyless entry. It takes a special chip inside PKE to get it done.
Source: http://www.planetanalog.com/features/communications/showArticle.jhtml?articleID=175003146

Excerpt:
"Encryption support
The patented KEELOQ global-standard cryptographic technology provides cost-effective, authentication, keyless entry, and other remote access control systems, as noted in the figure below. KEELOQ utilizes an industry-proven code hopping encoding methodology. The code changes when the encoder device is activated, and the code is securely transmitted. With an implementation based on an encoder and decoder pair, the encoder is in the remote, and transmits a rolling code ID number and counter value. The decoder is in the receiver and decodes the message sent by the encoder remote. It stores the Identification numbers and counter values of the remotes that it has "learned". The decoder allows access only to "learned" remotes. KEELOQ encryption is a highly secure algorithm that is achieved by means of a complex equation and randomizer with a 32-bit result. For parking-lot entry applications, a person can drive onto the parking lot without stopping, because the system recognizes the PKE transponder within an active zone of about three meters. "

 

[CX9 SportOwner]

For obvious reasons I'm not going to get more into this. Suffice to say, it's not as difficult as it sounds to crack. The good news is there are a relative few people who know how, and most aren't car thieves. The type of thieves that can scan and pop your car would never be going after a Mazda, either. That's why modern keyless systems are considered secure.

 

[ceric]

For obvious reason, I am not going to tell you how to steal a vehicle with high-end chip authentication either (I should know because I am an computer & electrical engineer by profession). However, I can tell you that it does not involve cracking the codes on site.

Any vehicles that cost less than $40K with chip authentication are unlikely to be stolen due to higher effort involved. There are plenty of luxury ones to steal.
PKE does not make stealing difficult. PKE just makes accessing your vehicles more convenient. Breaking the window and pulling the latch is certainly much faster.

 

[Lindyrect]

Breaking the window and pulling the latch is certainly much faster.

I ask because I am ignorant, but even if someone was to break-in, is it even possible to start the vehicle without the FOB/key? (uhm)

 

[CX9 SportOwner]

I'll see your computer & electrical engineering profession and raise you an Electronics and Communications specialist. (retired)


Lindyrect, it's possible, but the common thief won't know how. It's that RFID that tells the car it's you, and allows it to start. That unique code is what gets grabbed, and retransmitted.
Opening the doors is more akin to your automatic garage door, with the rolling codes Ceric was talking about. Still pretty easy to defeat, IF you know how and have some pricey equipment.
If thieves have that kind of technology, they aren't out grabbing random cars off the street. They are filling specific orders for oversees clients by searching the registration databases and scouting upscale clubs and restaurants, etc. Geez, I sound like a car thief.


Our biggest worry is the smash and grab, or straight vandalism, so don't leave valuables in the car.