Phone as a key PAAK - how does it work?

[Oakland]

I'm a new Mach E owner and still trying to get into a flow with PAAK. I find that if I know how a new gadget works, I can then better understand it's quirks and limitations and often even with imperfections, I'm still able find a workable relationship with the gadget.

I'm at a loss with PAAK. Sales person at the dealership, tech person at the dealership, tech person at the mothership Ford --- can't get a straight answer from anyone as to how PAAK actually works.

Some specific questions: When approaching the vehicle, how does PAAK decide to unlock the doors? When walking away, how does PAAK decide to lock the doors? Bluetooth connection gain/loss (respectively)? That plus phone GPS close/far from car (respectively)?

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[RickMachE]

It communicates via Bluetooth. Works like the fob.

It does NOT unlock anything. You unlock when the phone, or fob, is in your pocket and you push the door / hatch button.

 

[honourx]

What I don’t understand is why the PAAK is not 100 percent reliable as the fob.
I use the PAAK because I don’t like carrying extra items if I don’t need to. But why do i need to have the phone in my hand held next to the door…etc etc.

 

[Mirak]

What I don’t understand is why the PAAK is not 100 percent reliable as the fob.
I use the PAAK because I don’t like carrying extra items if I don’t need to. But why do i need to have the phone in my hand held next to the door…etc etc.

Because the Bluetooth system isn’t as reliable as the fob’s RFID. Why it isn’t as reliable is one of life’s great mysteries. Maybe it’s a problem with the car, maybe it’s a problem with the phone, maybe it’s a mix of both.

I suspect the problem is mainly on the phone end because waking your phone up by taking it out of your pocket seems to enhance the connectivity.

 

[Logal727]

What I don’t understand is why the PAAK is not 100 percent reliable as the fob.
I use the PAAK because I don’t like carrying extra items if I don’t need to. But why do i need to have the phone in my hand held next to the door…etc etc.

It’s mostly on the phone side and the limitations of the Bluetooth LE spec, the fob only has one job to do while the phone has to juggle a bunch of different connections and calculate distance and keep connections stable, etc

 

[Mirak]

Has anyone tried copying their fob to an RFID sticker and just sticking that to the back of their phone? I suppose that would screw with wireless charging but I wonder if it would otherwise work?

 

[226ra]

It doesn’t.

 

[SpaceEVDriver]

What I don’t understand is why the PAAK is not 100 percent reliable as the fob.
I use the PAAK because I don’t like carrying extra items if I don’t need to. But why do i need to have the phone in my hand held next to the door…etc etc.

The fob has one job. The fob regularly broadcasts its signal and the car listens for it, checking each fob ping for a specific encryption key, and then reacting under a well-defined, specific set of conditions. The fob operates in the 315 MHz frequency, which allows farther distance communication than bluetooth.

The phone has multiple jobs related to bluetooth. And the bluetooth technology for connecting to multiple devices (car, headphones, etc) simultaneously is still pretty lacking. The communications between the phone and the car require multiple back-and-forth negotiations, so it takes longer to negotiate what you're asking it to do. And because it operates at 2.4 GHz, the phone has less time to respond (because higher frequency means shorter usable distance, in general) before you're yanking on the door or already out of range.

 

[SpaceEVDriver]

Has anyone tried copying their fob to an RFID sticker and just sticking that to the back of their phone? I suppose that would screw with wireless charging but I wonder if it would otherwise work?

RFID doesn't operate at the same frequency as key fobs.

 

[Logal727]

Has anyone tried copying their fob to an RFID sticker and just sticking that to the back of their phone? I suppose that would screw with wireless charging but I wonder if it would otherwise work?

RFID in the fob is only for the spot in the center console, wireless in the fob is Bluetooth LE

 

[ChuckA]

What I don’t understand is why the PAAK is not 100 percent reliable as the fob.
I use the PAAK because I don’t like carrying extra items if I don’t need to. But why do i need to have the phone in my hand held next to the door…etc etc.

The Bluetooth disconnects rendering the PaaK inoperative. Make sure you setup or remember your door code and setup a backup start key code. I use these all the time when my PaaK fails. I have a 2nd keyfob but don’t want to carry it.

 

[Oakland]

Interesting that the first response states "It does NOT unlock anything" - for me, it's the one thing the PAAK DOES do well.

If BT is the way the car makes decisions on locking vs unlocking, does anyone how the car will behave in this scenario - location of where the car is parked at home is within BT range of high traffic areas within the house (eg living room, home office, kitchen, etc). This is my situation and I'm afraid the car will spend some amount of time unlocked when I don't want it to be unlocked.

 

[SpaceEVDriver]

Interesting that the first response states "It does NOT unlock anything" - for me, it's the one thing the PAAK DOES do well.

If BT is the way the car makes decisions on locking vs unlocking, does anyone how the car will behave in this scenario - location of where the car is parked at home is within BT range of high traffic areas within the house (eg living room, home office, kitchen, etc). This is my situation and I'm afraid the car will spend some amount of time unlocked when I don't want it to be unlocked.

I turned off PAAK when I was staying in a motel and parked the car right outside the door. I noticed its lights came on when I walked past the motel room door. I left my phone and fob on the counter near the door, went out and checked, and the doors were not locked. I don't know if it failed to lock it or if it somehow allowed it to unlock. But I turned PAAK off right away and don't use it. It *shouldn't* work this way, but I don't trust it.

I don't mind having a fob; I have to carry other keys with me anyway.

 

[RickMachE]

Interesting that the first response states "It does NOT unlock anything" - for me, it's the one thing the PAAK DOES do well.

If BT is the way the car makes decisions on locking vs unlocking, does anyone how the car will behave in this scenario - location of where the car is parked at home is within BT range of high traffic areas within the house (eg living room, home office, kitchen, etc). This is my situation and I'm afraid the car will spend some amount of time unlocked when I don't want it to be unlocked.

No, it is not unlocked. Phone nor fob. Lock car. Leave phone and fob in house in range. Try and open car.

 

[macchiaz-o]

No, it is not unlocked. Phone nor fob. Lock car. Leave phone and fob in house in range. Try and open car.

Rick is correct. And if you think about it, this is probably one of the reasons PaaK is so complicated to get "just right."

The vehicle detects your key at a medium range, let's say around 20 feet away. It wakes up a few of its modules, and it greets you with lights (if you have this enabled).

The vehicle also must detect that you have the key in very close proximity to a door. If you do, then the vehicle will allow you to open a door (unlocking them in the process), or if you're standing by the tailgate with the key, you can open the tailgate.

The complicated part is how the car grades your proximity to authorize a welcome or a door unlock or neither. Are you just nearby or are you standing right next to a specific door handle? Ford uses several antennas* and either an RF receiver that is rapidly commutating between them, or several RF receivers. (I don't know which, but I'd guess the former.) The receiver must measure signal strength at each antenna to gauge distance and specific door proximity, while also decoding and verifying the transmitted code to see if it is authorized.

Anyway, this is how I believe it all works between a factory key fob and the factory-built vehicle. They are a matched pair and in RF terms, this allows for a nearly perfectly "matched filter." The characteristics of a key fob, even how it slowly changes as its battery loses energy, are extremely well characterized and we have decades of refinement and perfection in this area.

Now add in PaaK... It's flaky. It's not as graceful experience as a key fob. It relies on FordPass which is also flaky. But it's at the same time extremely impressive to me. It was a huge challenge to implement a key that is secure, operates on random phones that largely didn't even exist when the vehicle was engineered (and certainly weren't designed in cooperation with engineers doing the vehicle-side of PaaK), and are using a comparatively bulky/complicated general purpose waveform -- Bluetooth -- instead of a trivially simple key fob rolling codes waveform like in our fobs.

And then add into that the challenges of iOS and Android doing whatever they can to keep energy consumption low, including limiting 3rd party app Bluetooth transmissions, and the car's challenge of detecting which door the phone is at when every phone model has different antennas, transmission levels, and even different transmission timing. It's crazy that it works as well as it does, and it's no wonder we also have a backup start password!

* There is an antenna per door, tailgate, and possibly even an antenna or two in the cabin or inside the cargo area. On my last vehicle, the 2014 Ford Fiesta, the car could sense if the key fob was left inside the hatchback so that if you set it down while loading groceries and forget it's there and you close the hatchback, you won't lock yourself out. After you close it, the tailgate will just unlatch again and the car will honk to let you know your error. I don't know if the MME also does this but I wouldn't be surprised if it does... even though it's less useful since we have door codes, phones, and so on.

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