Prius Lost All Keys SKS Smart Reset (Program Used Fob)

Hey all,

New member here. Not new to forums and because the 4 Prius' I've owned have been flawless, I never had a use to join this forum, but today I decided to join to share a little tidbit of information I learned. Now for the most part this is pretty intuitive to someone with mechanical and IT experience, but as more and more people start to tinker with their vehicles by themselves, it might not be to the average consumer.

I will save the back story, but I had a Prius with no keys. They were for all purposes, lost and not going to be found. This led me down a rabbit hole of finding out that the only way to program a Prius SKS (Smart Key System) key fob is through a Toyota Diagnostic/Programming software called TechStream (TIS). Now this software can program new keys if you have an existing one, without much effort. There are some threads on Prius Chat that I've found useful that outline these steps. (See here: Techstream Key Fob Programming – Step by Step with pics | PriusChat)

Now if you lose all your keys, you will need to do the "Smart Code Erasure" function under Smart Key > Utility menu. This will provide you with a "Seed Number" and will be either 6 or 96 characters in length (depending on what version of TIS you are using. This "Seed Number" will need to be inputted and calculated to return a "Pass Code Number" which will be required in TIS to complete this procedure. This "Seed Number" calculation can only been done legally by Toyota Authorized Dealers or Locksmiths who are licensed. Obviously the whole reason you are reading this is because you are a DIYer and with that I will say there are alternate methods to get the Pass Code.

Once the Pass Code is inputted there is a 16 minute reset procedure/countdown. Once that is completed you can go back to the Smart Key > Utility menu and select "Smart Code Registration" and follow the instructions to register a new key. It will ask for an existing key, but you can ignore that step and just continue to register new fobs.

This same procedure is the ONLY way to register used key fobs (that are linked to another Prius) to a new Prius. You can link a used Key Fob only if it has been "Virginized" which is to say that it is, for all intents and purposes, a new key "mentally." There are people/companies that offer this service. I've noticed that buying a new Fob (currently in 2021) is cheaper ($99) than buying a used Fob (~$50 - $75) and getting it "virginized" (using online services (~$25) I've found) or using this procedure to do a "Reset" and use a used fob. I would strongly advise against using a used Fob in a situation where you already have one working Fob. This hassle and the possibility of something going awry outweigh the $50 you will save. Only in a situation where I was already having to reset the SKS due to losing all keys, or if I have one readily available, would I even consider using a used Fob.

This price does NOT cover the price of physically cutting the key blade which you insert into the door handle.

All of this information has been posted before, but it took me 3 days of digging to find it and I hope a top level post will help anyone in the future.

During this whole process I learned two things that I didn't run across or wasn't obvious.

1) Have your battery 100% charged if possible! This is important. Either use a battery tester, volt meter and check, or just be on the safe side and take the battery out and take it to your local auto parts store to charge. The Prius battery is pretty small and can be fully charged in around an hour. Obviously the system will not stop you if your battery is low, but the last thing you need is it dying in the middle of the reset.

2) The "Seed Number" changes and is only valid for 10 minutes (IIRC). Meaning if you close the program, or wait 10 minutes, the Seed Number will change and you will need a new Pass Code Number.

3) Because you have no keys, you cannot start the car. Because you cannot start the car, TIS will NOT auto populate your VIN number. It will also NOT connect to your car automatically. You will need to manually input car information. When you select "Smart Key" in the main TIS menu it will NOT connect. At this point you will want to press the cars Power On (Push to Start) button. The car will give you an error that there is no key detected, but once the car is "awake" you can select the "Smart Key" function in TIS and it should connect to the SKS module and let you continue.

Once again this procedure is ONLY for a situation where you have lost ALL your keys to the car OR if you want to program a used Key Fob to your Prius.

Hope this helps someone in the future. I would strongly advise reading the thread I posted in this post to get familiar with the Toyota TechStream (TIS) software and screens that I mentioning in the post. I was in a hurry so was unable to capture the process to document.

 

First of all, sorry for the late replies. I never got notified of these replies!

There is a max number, without going to the car and hooking up the software, I couldn't tell you what it is. Off the top of my head I think it is 4 or 5 however.

Correct, if it is "virginized" then you can program it as a new fob. If you already have one fob, there is no need to do a reset. If you don't have an existing fob, then a reset is required, whether you have a used key, a new key, or a "virginized" key.

This procedure is for 2010+ Priuses. Sorry can't help with an older model. I believe the software is able to do that however and program the buttons.