How to Muzzle a Smart Key's Emissions?

tin foil.

 

Aluminum foil works just fine. So does a small metal box, assuming the cover makes good contact.

The fob does not transmit on its own, but only when queried by the car. Inside a Faraday cage it sits quietly without wasting power.

Tom

 

Get a black backed FOB and program it to work on your wife's car. Just carry the key, and leave the FOB in the draw under the arm rest.
Or, you can do what I did, which is to use a standard remote. These can be programmed so the same remote will open both cars. I keep my smart key in the slot all the time (except when I park in NYC when I leave it in the draw) See:
http://priuschat.com/forums/gen-ii-prius-modifications/66652-smks-bypass-cheap-alternative.html

 

Several things that you can do to reduce the key contingent:

1. For each keyfob, add it to the transponder ("key in dash") list for the other car. While a keyfob is tied to a single car for the SKS and remote button functions, it can be added to any number of cars for use in the keyslot. The only limit is a maximum of 5 transponders for each car. Use the instructions at http://priuschat.com/forums/knowled...lly-how-program-non-sks-key-fob-detailed.html

2. Duplicate the small mechanical keys from each keyfob onto ordinary size Toyota keyblanks. Any place that duplicates keys can do it for about $2 each.

You can now carry one keyfob that has full function on one car. For the other car, you can use a mechanical key to lock/unlock the door and the same keyfob inserted into the dash.

You could rekey the door lock on one car to match the mechanical key for the other car. That way you wouldn't need to carry an extra mechanical key. You probably would want to replace the small mechanical keys with official keyfob size keys cut for the new key cylinder. Blank mechanical keys are about $7 each at a Toyota parts outlet. Getting them cut may be a problem at cheap key duplication places, so this is probably a job for a real locksmith or a Toyota dealer.

 

You are right - any Faraday's cage would do, so any container made of conductive material. If I remember correctly, the FOB is a
RFID device, so it does not transmit anything on its own, as Qbee42 said. There is a transmitter in the car, in the proximity of the door handle, which periodically broadcast queries whether a FOB is somewhere around. The FOB only answers the call. If the FOB really did transmit anything on its own, the little battery in it would not last very long.

Or, you can disable the SKS function at all, or remove the battery from the FOB, and use it as a passive RFID device - it would still work when plugged into the socket on the dashboard and would allow you to start the car, even without the battery inside.

 

Location of the coils can be found in the user's guide (it is in the direct vicinity of the handle on the driver and passenger doors and on the hatch), but I don't think you'll be able to find a dead spot within the car. I tried, but the location of the FOB works extremely well. The car was able to locate it anywhere within.

 

It probably won't work on a Prius, but back in the "good ole days" I had a Ford pickup and a Lincoln town car at the same time. Back then, even though the key was double-sided, the tumblers in the lock only read one side. I had the locksmith make me a key with one side cut for the truck and the other side cut for the town car.

All I had to do was put the key in one way for the truck and with the other side up for the car. (One key, two cars)

 

There does seem to be a dead spot on the floor behind the front seats - I once gave my GF the second fob while I had the main one - we were traveling in Oregon, and I wanted her to be able to get in the car if we got separated. She left her purse (with fob) in the car. I was able to lock the car with SKS normally a few times, but at one stop it protested with a long beep. I discovered then that she had left the fob in the car.

If you really wanted to keep the second fob in the car, you could get (or make) one of those magnetic key holders (metal box with magnet attached) and then attach it under the front seat to the metal seat frame.

Keep the magnet away from the hall effect accelerator pedal - we don't want to read about your car taking off into a field unexpectedly. :madgrin: