My experience in getting a replacement FOB

I think you got it h00k! Good summary!

The key point is: to add a fob, new or used, you first have to power-on the vehicle, so that you can connect Techstream (or equivalent). So, you need a registered fob to begin.

If you've lost all fobs...

See:

http://priuschat.com/forums/gen-iii...998-programming-ourselves-10.html#post1284452

 

That sir, is the golden nugget!

Those few words explain the logic. Perhaps adding a few procedures on how to program the module would (or should) put this to bed.

When I get time, I'd like to buy one *new* OEM fob, and one *used* ebay OEM fob, then program the car to accept them all - thereby proving what is thought to be true - is.

Safe trips

 

Hey, it's your money but...

If you have access to the seed/passcode lookup, then the used fob will work fine (and cost about $50). If you have to pay someone else for the seed function, it will be $100-$300 for the privilege.

The new, never paired, fob will work fine using just the Techstream add-key function. A new fob should be available online for less than $200. If you want to experiment, a new fob may work using the chicken dance described in http://priuschat.com/forums/knowled...lly-how-program-non-sks-key-fob-detailed.html . Use the 13 step procedure or one of its variants. The 5 step procedure is for the transponder on Gen2 keyfobs.

A big reason there is so much conflicting information about the keyfobs is that there are 4, maybe 5, different mechanisms being described. The Gen2 non-SKS keyfob uses a Microchip controller that is fully documented (rolling code, 128 use setup limit if enabled, etc.). The Gen2 SKS keyfob uses a controller that is different (and undocumented). Both SKS and non-SKS Gen2 keyfobs have a separate transponder in them that is used for the fob-in-dash function. Gen3 keyfobs are yet another animal, although they are programmed in a manner similar to the Gen2 SKS keyfob. The Gen3 keyfob doesn't have a separate transponder in it, although it does work without the battery when held near the Power button.

The only place I've seen Toyota mention the VID is as an error condition when registering a Gen2 SKS keyfob. It may also be there for Gen3 - I haven't noticed. Paul at Art's Automotive wrote several articles for a mechanic's trade magazine where he describes VID as the Vehicle ID. Check his web site for a link to the magazine. My understanding is that the VID is broadcast by the car, and any keyfob that recognizes that VID responds. Thus multiple keyfobs can have the same VID. Additionally, each keyfob has a unique serial number that is registered in the car. In order for a proximity lock/unlock to work, both the vehicle ID and the serial number must match up.

The reason I think the VID can be programmed multiple times is that a used keyfob that produces the VID-mismatch error can be made to work after a seed reset. The VID-mismatch goes away.

 

Well, I'm almost ready to 'put up' rather than 'shut up' - my factory direct fob should be here this afternoon.

I'm also bidding on one *used* fob - and already won one uncut laser key. Once they come in, my experiment will begin.

 

opcorn: subscribed

 

Well, adding the *new* OEM fob was anticlimactic (TS & Mongoose).

Connect ODB cable, start TS, access the SKS module, select New SKS Registration, add new key. Screen shows 2 keys registered, five slots left. Hold the original fob to the Start button, beep, hold the new one up to it. Done. Took about five minutes from netbook boot to shutdown.

<RobH> You seem to be the most fluent in this and I am beginning to finger you as the resident 'Expert". The more I read the evolution of your posts on this topic, the more of what you say seems true (logical to me). It took some some weeks to appreciate the insight you have on this, and assertions you made then only ring true now. When my used Ebay fob comes in, I'd like to maybe hit you up with IMs. I am believing a full SKS reset is required (TS with re-seed) to get full SKS/Remote functionality out of the used fobs [aftermarket methods excluded]. In my case, I only want to cut a replacement key, and then program the module to accept the used fob to start the car - SKS/remote features not wanted - so I think a re-seed is not going to be necessary. I'd also like to chat with you about seeding software.

Summary to date ('11 Prius 2) with an original (SKS silver) fob:

• TS/Mongoose/Factory fob & a virgin SKS (silver) fob = full SKS functionality.

Note: I noticed that before starting this, there was an entry in the TS SKS tab, "Master" [key] ... none. After registering the new fob, my original fob became a "Master", and TS reported "Master" ... yes. I immediately took the "Master" fob off my keys, marked it as such and stuffed into the drawer... replacing it with the newly registered fob.

Also, there seems to be two SKS reset options, a full on Reset and cleansing of the module, and a lessor one, something akin to erasing current information..

 

I never had a problem with an unused FOB. In fact, it took about 4 years for the battery on the main FOB to bite the dust. I took the second FOB out of the safe and it worked just fine, again for about 4 years. That second battery died last week and I just replaced the battery in the first one and it worked fine (after 4 years with no use AND a dead battery).

I think I've stressed the system well enough.

 

The Gen2 keyfob systems use both a transponder and a RF link. The transponder system is the one that can be activated without a seed reset, even with a used keyfob. The Gen3 keyfob system doesn't use a separate transponder.

The consequence of this is that programming a used Gen3 keyfob, even just for use with the ignition, is going to need a seed reset. I'm convinced that the whole seed process is implemented in Techstream, so a program like some locksmiths use may have a different security mechanism. There is a security handshake between Techstream and the car that is separate from the seed/passcode lookup. So the seed is used by Techstream to validate the person running it, and there is another security handshake used by the security ECU to validate that it is communicating with an appropriate program (Techstream).

I don't know if you can add a used keyfob after performing the "erase all but the current key" function in Techstream. I doubt it, but it's sure worth a try.

Cutting a mechanical key with the inside slot design is an expensive process. The going price seems to be $35 per key at my local locksmith who actually has the equipment. And even that guy refused to attempt cutting the Lexus pattern on a Prius blank. Think I've got my excuse for getting a mini milling machine that I've wanted for some time...

 

That makes sense, given my budding knowledge and developing experience.

I got my used silver-back fob yesterday - just got in trying to *Add* it, like I did with the new OEM fob. It failed totally.

Back when I *Added* the new fob through TS, I only had to touch the original fob, then the new one. The registration was finished. When I (moments ago) tried to *Add* the used fob, a new screen advised to set the fob on the passenger seat. It timed out and failed. Note: I tried the 'test' function with the Master fob, where TS asks you place the fob in different areas of the passenger compartment - I never had success with the Master fob registering success, so I'm not sure what the second failure meant with the used fob on the passenger seat.

My next step will be to try the "Erase" function (maintaining the Master key info), to see what occurs. I think I'll be safe since I am not erasing the Master key, hence, I'm thinking I will be able to re-register both the original 2nd fob, and the recently added new OEM fob (all three should retain their original VID/registration with the ECU). The used may still fail totally. Sound correct? I need to think this through before I commit to doing it.

After I try that last option, I believe it will prove Gen3 SKS needs a re-seed to add a pre-registered used fob. I'm going to send you an IM real quick regarding this.

I appreciate your time in replying. The things you say make sense, even if I am not fully understanding everything you say. For some reason however, it just 'rings true'.

 

Thinking out loud (or trying to reason)...

What is the security justification for requiring a level 3 (locksmith/dealer) re-seed to add a used fob when one has a working OEM fob that puts the car in the Ready state?

I can see not having any working fobs, but if I have at least one that will start the car, why is adding one that does not start the car make a security risk... I'm not understanding the reasoning

Rob: Sherline lathe?

 

The security issue with a reset is the creation of a key when none are available. It wasn't until 2008 or so that it was discovered that doing a seed reset allowed reuse of old keyfobs. Before then, used keyfobs could not be restored to full function at all. But the technique works on all 2004+ SKS systems.

It appears that there was never any intention to allow reuse of old keyfobs. The process seems to be more of an Easter Egg than a design feature.

Preventing reuse of old keyfobs could be argued to be a security feature. It certainly increases the sales of new keyfobs...

Having a seed reset function is actually an improvement over the system used in Gen1 Prius. If you lose all the keys for a Gen1, the official procedure is to replace the security ECU ($$$$). The unofficial procedure is to remove the security ECU, ship it to a company that rewrites the EEPROM to new condition, ship it back and reinstall.

 

Proxxon Mini Mill. Several people have modified their manual mills for use with CNC. Here's a utube of cutting a Toyota key with one: http://www.youtube.com/watch?v=W-G6tWZxnEU . CNC would be really neat, but manual operation should work for one-offs.

 

That would make sense. When I go into TS later, I'll have to see if there is a difference connecting with the Ready light on, and ready light off. If the SKS options are the same, then I will still be confused. The re-seed should be required when no keys are present, and not required when a registered key is present.

Btw: I availed myself of the information I sent you in the IM. I'll let you know how it goes.

 

The ECUs have to be powered up for TS to work. The Body ECU wakes up when you open the door, but will go back to sleep if there is no further activity. I think it's the Body ECU that identifies the vehicle type (VIN and such), so if it's asleep, the auto-recognition in TS isn't going to work. But you can still manually enter the data. During a power-off seed reset (16 minutes), the Body ECU is going to go back to sleep, which I suspect will kill the reset. You can keep the Body ECU awake by pressing the switch on the door frame that detects an open door. Just how often is an exercise for the reader...

 

Ahh, that explains an instruction I recently got about "leaving the door open" during the Reset.

I may proceed later this morning - I'll update if I do so.

Rob, I can't seem to say it enough, but thanks. Every post & reply you write seems to have some tidbit of information that appears to justify listening to you :rockon:

Note: TechStream released v. 7.00.020

 

Ok, I can confirm on a 2011 SKS, to add a used fob, a Reset & re-seed is required.

RobH: you have a PM.

 

Great info from you and RobH. Thank you very much for the confirmation!

 

Great info here and sorry to bring up an old thread, but I'm looking at adding more keys to my Highlander and would love to be able to buy used fobs on ebay and marry them again to my vehicle (ie keyfob has been burned already so the ECU needs to be reprogrammed to accept it).

So out of curiosity, where is the best place currently to get a pass code created?

If the passcode is too expensive then obviously the used keys become less of a deal and it might be best to stick with just buying new keyfobs instead.

 

I've already got mini VCI to learn the new keys so all I was concerned with is whether I needed a seed code or not......sounds like the answer was no if you still have a working master smart key.

Successful SKS Reset using Mangoose cable and used Keyfob registration | Page 2 | PriusChat