Will one SKS fob run two priuses?

That would be a crazy idea if it worked. So if you sold one of the cars, the buyer can come back for your 2nd car?

 

Most people complain about interference between two SKS systems because it is a bad thing. How hard is it to keep two different SKS fobs?

My wife and I haven't had any problems with our two Toyotas.

 

The "plug the fob in the dash" function can be registered for any number of vehicles. There is a limit of 5 registered fobs for each vehicle. Since a fob can only know about one vehicle ID, the remote functions are limited to a single vehicle.

It makes sense to me to cross register the fobs. That way you have the option of using the "wrong" fob if it's the only one available. But that's an emergency backup, not an every day usage. You'll still have to have a mechanical key to lock/unlock the driver's door.
You could have a locksmith recode the mechanical lock in one of the cars to match the other car.

This is all specific to 2004-2009 models. 2010+ are different.

 

By "remote functions" are you referring to the remote lock/unlock only or the SKS functionality or both?
It's interesting to me that the key ever gets programmed, rather than each key simply having a unique ID which it broadcasts and the car recognizes.

 

Only if you forgot to unregister that fob from the car you kept.

I understand this thread's about Gen 2 and I've got a Gen 1, so the procedures might not be the same, but mine has a 'forget all except this one' function, so you don't need to still have the one you're unregistering ... even if you only remember to unregister it after the buyer is gone, you still can. You just tell the car to forget all except the one you're still using.

Still sound so crazy?

-Chap

 

Yes it's still a pretty crazy idea. I would be interested to know if anyone has used 1 fob to start 2 cars.

 

I have a little different question about fobs. I have a 2004 base Prius and I accidentally bought a silver logo fob SKS. It can't be programmed to open the doors but can run the car. I was thinking about buying a black logo fob and either keeping the SKS fob it for an emergency or de programming the fob from my car and selling the fob. My question is can I de program the fob?
I know that I can delete the fob from my car.
I have a mini-vci to do that with.

 

I think you should be able to sell that FOB as is. It didn't get completely programmed. Maybe you can list it for sale here and someone will take a chance on it.

 

There are actually 3 different electronic locking systems on a Gen2. The "plug in the dash" one is an ordinary transponder chip that is used in most modern cars. It is used in both SKS (silver logo) and non-SKS (black logo) vehicles. Note that the power to operate the transponder comes from the car, thus the condition of the fob battery is irrelevant for "plug in the dash" operation.

The black logo fob is a transmit-only device, which the car is trained to recognize. I suppose a single black logo fob could be registered on multiple vehicles, although they would soon get out of sync with the rotating usage code. Each time a fob key is pressed, a usage count is incremented, and the car expects that count to be within some small range of expected numbers. Too many usages on one car would put the number out of range on the other car.

The silver logo fob has a receiver in it that listens for a car broadcast. The range is about 3 feet and includes a unique vehicle id. The vehicle id is programmed into the fob if the fob has never been registered, OR if the vehicle has zero currently registered fobs. There are 5 car transmitters located in both front doors, the console, inside the trunk, and outside the trunk. The location of the fob is determined by which car transmitter causes the fob to reply.

The silver logo fob has a transmitter that is used whenever a key is pressed, plus whenever the fob recognizes a vehicle id that has been broadcast by a nearby car transmitter. So for SKS to function, the fob has to recognize the car, and then the car has to recognize the fob.

The problem with used SKS fobs is that they have already been programmed with the vehicle id of a single car. A never-registered fob can be registered with the chicken dance or Techstream. In order to register a used fob, it is necessary to do a "seed reset" with Techstream (or the locksmith equivalent) in order to reset the registered fob count to zero. Techstream requires a unique password to perform the seed reset. Only techstream users with a "Security Professional" account have access to the password lookup... plus this guy in Lithuania who sells passwords...

 

the answer is 'yes', the real question is 'how'?

 

Thank you for the very in-depth post. Fascinating.

 

So does that mean if you do a seed reset on 2 cars, you can program the same fob to be on both cars?

 

Interesting question. You'd certainly only get proximity functions with the last car registered. But the remote buttons might work with both cars. There might be problems with the usage count getting too far out of sync between the two cars.

The transponder is registered with the short chicken dance or with the "Immobilizer" dialog in Techstream. The SKS functions are set up with the long chicken dance or the "Smart Key" dialog. A seed reset requires a password in the "Smart Key" dialog.