Pushbutton start question

[AMCRambler]

Wondering if anybody on here has a newer car that has the push button start where you don't need a key for the car? I remember hearing on some of the newer vehicles, there is a fob that acts as the key for the car wirelessly? So basically there is a button on the dash to start the car and as long as you have the fob in your pocket you can push the button and start the car.

I started thinking about how these work and I'm sure it has some type of proximity sensor to it so that when you're further away than say 10 feet it won't start. What happens if you leave your keys on the roof of the car and drive off though? Or perhaps you leave them sitting on the hook in the garage? The car is close enough to let you start it, but after you drive off what happens? Does the car shut off? Will it keep running? What happens when you get where you're going and turn the car off? Oh shit, I forgot the fob and now you're stuck?

Just curious if anybody knows how these work and if they are idiot proofed?

 

[KDKPSJ]

In my G37, if the key is on roof, the car realizes it's outside and won't start. I am not sure about the other brands, but Nissan/Infiniti did a fine job placing the radio sensor in proper place, and I haven't experienced any misfunction. Even those tricky places you mentioned, it's been working ok so far (1.7 years of ownership).

If the key is removed after the car starts, the car doesn't shut off. But the warning light is on saying key is missing. If you ignore that and you're stuck, too bad, but it's your fault because you ignored the warning.

 

[Don Vito Corleone]

My 2006 BMW 330i has this feature. I think it can definitely tell if the key is inside or outside the vehicle because it won't let you lock all the doors and the trunk with the key in the car. I assume, then, that it won't start if the key is outside the car.

Interestingly, the first day I got my car I was at lunch with some colleagues and learned I had a meeting sooner than I realized, so I needed to have them drop me and drive my car back to our garage. I inadvertently left the key in my pocket. One of my colleagues managed to stall the car in traffic on the way back (not sure how - the clutch is very forgiving), and learned that the car will allow restart without they key present for 10 seconds after it stops running. Not sure why BMW designed this in, but they did.

 

[LTC8K6]

Yep. My Jeep knows where the key is somehow. I have never been able to fool it.

 

[thescreensavers]

All the cars that have this system only work with the key inside to start the car. From my experiance.

 

[hanoverphist]

My 2006 BMW 330i has this feature. I think it can definitely tell if the key is inside or outside the vehicle because it won't let you lock all the doors and the trunk with the key in the car. I assume, then, that it won't start if the key is outside the car.

i sometimes help out at my friends shop, and i try to move the fun cars in and out of the bays. bmws wont start if youre outside the car with the fob, but they will stay running.

 

[HarryLui]

http://www.youtube.com/watch?v=34yCk723YNM

 

[MotF Bane]

In my G37, if the key is on roof, the car realizes it's outside and won't start. I am not sure about the other brands, but Nissan/Infiniti did a fine job placing the radio sensor in proper place, and I haven't experienced any misfunction. Even those tricky places you mentioned, it's been working ok so far (1.7 years of ownership).

If the key is removed after the car starts, the car doesn't shut off. But the warning light is on saying key is missing. If you ignore that and you're stuck, too bad, but it's your fault because you ignored the warning.

That's an impressive degree of accuracy.

 

[Saga]

http://www.youtube.com/watch?v=34yCk723YNM

Anything Dodge is a piece of shit, this is no surprise.

My BMW will not start unless I am in the passenger seat. It's extremely accurate, I can stand IN the door with someone else sitting in the driver seat and it will not start.

 

[alfa147x]

http://www.youtube.com/watch?v=34yCk723YNM

bad ass looking car but that is just ridiculous!

 

[LTC8K6]

I agree with the commenters. The Challenger would not have started.

It was either rigged, or that one was defective.

 

[rh71]

comfort access here on a bmw... I honestly don't know how it is able to save battery while always detecting whether the key is in proximity (opening the car door for example). I tried to read the technical doc on it and I was completely lost.

At any rate, this is what I've found...
- key must be inside for start button to work... many times I have to buckle my kids in the back but want to open the windows first via the driver door switch so I have to turn the car on... I can't do it just by reaching in... I have to cross the driver door threshold with the key. (Yes I know I can open all windows with the fob, but I just don't want to take it out)
- idrive persistently warns you if the vehicle is on and the key is not detected inside, so this way I can't walk off into the airport and my wife drive the car home not realizing there's no longer a key. Also explains the key-on-a-hook in the garage question the OP asked.
- yes the vehicle stays running once on even if keys move outside... great for when you need to run into the store for 30 seconds and not needing to turn your engine off. You can still hand-touch lock the door. Use this all the time.
- can't lock the vehicle if the keys are inside the car, same with the auto-tailgate... won't shut if all other doors are locked.
- sucks for washing your car cause everytime I spray the doorhandle inadvertently the door locks/unlocks... I have to leave the key inside the car to avoid this.

Comfort access is a god-send with kids and their gear. I drive my dad's minivan sometimes and the hassle of actually opening and closing a full tailgate with shit in your hands... ugh.

 

[RKS]

When can we expect embedded RFID chips so we can do away with fobs/keys?

 

[AzNKiD]

I believe they are using RFID in this system already, at least with the BMW comfort access. I remember reading a thread about this subject over at e90post forum. it uses passive rfid to communicate with the computer, and the batteries is there for the buttons only. look at your bmw fob key, there is no metal contacts, and if its out of battery, you can still start your car by putting it in the slot.

Not sure if you guys know, while the encryption for these type of system is still secure, they have found a work around to beat it already. it involves using a transmitter and receiver to trick the car. they point a receiver towards you with the keyfob, and then transmit the communication to their receiver to open/start your car while you would be miles away. its a middle men type attack, basically extends the distance of the keyfob signal. wouldnt worry too much at about this attack unless you drive a super/exotic car.

 

[DivideBYZero]

When we had a 2006 Renault Clio with this system it worked like this:

- Fob in car, car will start, even if it was in the Wife's handbag in the trunk
- If the fob was left in her handbag in the trunk, car wouldn't lock (hidden pushbuttons in handles, rear logo)
- If the car was running and the person with the fob on them got out, you received a warning on the message display to say it had noticed the fob had left the car, but it would still run.
- Car would only start if the fob was inside the perimeter of the car, it was very sensitive and accurate.

 

[amdhunter]

My RX-8 can definitely tell when the car is trying to start if the keys are outside of the car.

It can also tell when I am trying to lock the car with the keys inside (I can lock the car by pushing buttons on the door handles.)

 

[RKS]

I believe they are using RFID in this system...

no, I meant under my skin.

 

[Zap]

My mom's Volvo V70 has it. It is pretty good about detecting whether or not the fob is in the car - can't even accidentally lock it in.

With that being said, how difficult is it to turn a key? Some of the pushbutton starts I've seen still require the fob to be inserted into a holder (Volvos w/o the option, a 2011 BMW 328xi I test drove). If you still have to stick the fob into the holder, why not make you turn the fob to start it while your hand is on it instead of taking the extra step to push a separate button. Oh teh noes, I've just described the old style turning a key!

 

[JCH13]

I think the RFID systems can use highly directional antennas of limited range in order to control where the FOB/chip will work. I had an RFID ski lift ticket that needed to be within a few inches of the scanner to work.

 

[Zenmervolt]

The first thought that came to mind was having multiple directional sensors and then using triangulation based on signal strength at various sensors to determine the position of the fob.

Second thought that came to mind was having two sets of directional sensors, one set focused inside the cabin and one set focused outside the cabin. Then allow/disallow certain functions depending on which set of sensors was receiving the stronger signal. This seems likely to me since it would be the least computationally-intensive of the two methods that came to my mind.

ZV

 

[LTC8K6]

http://en.wikipedia.org/wiki/Keyless_Go

 

[amdhunter]

My mom's Volvo V70 has it. It is pretty good about detecting whether or not the fob is in the car - can't even accidentally lock it in.

With that being said, how difficult is it to turn a key? Some of the pushbutton starts I've seen still require the fob to be inserted into a holder (Volvos w/o the option, a 2011 BMW 328xi I test drove). If you still have to stick the fob into the holder, why not make you turn the fob to start it while your hand is on it instead of taking the extra step to push a separate button. Oh teh noes, I've just described the old style turning a key!

lol - my keys can remain in my pocket, but I still have to turn a plastic ignition.

 

[Zap]

lol - my keys can remain in my pocket, but I still have to turn a plastic ignition.

Is turning it so much more difficult than pushing a button?

My mom was talking about that with my aunts. For them, it is a huge "wow" factor, as in "wow I can start my car with a button!"

 

[amdhunter]

Is turning it so much more difficult than pushing a button?

My mom was talking about that with my aunts. For them, it is a huge "wow" factor, as in "wow I can start my car with a button!"

Not at all. I prefer it the way I have it. Easier to put on battery power and it just feels more right than a button.

 

[DivideBYZero]

Not at all. I prefer it the way I have it. Easier to put on battery power and it just feels more right than a button.

Eh, you get used to it. For push start it's one push without foot on brake for battery, then another with foot on brake for start, or just push with the foot on the brake once to just start. At least that's how BMW & Renault do it.