Key FOB programming help, went from SKS full function to Key in Slot only

2006 Prius

Before:
Had a single SKS key with no RFID chip, I will call this KEY A. This key would start the car as long as it was NOT inserted into the slot and it would open all the doors, do all the SKS things.

Plan/Intention:
I want to add a second key and be able to start the car with SKS or with key in slot with both keys. The reason is when I have loaned the car to someone they will often try to put the key in the slot and then call me saying, "the car won't work!"

Action taken:
I tried the chicken dance. It would not work because my working key, KEY A, did not have an RFID and so inserting it 5 times into the slot and open/close driver door 6 times would not put it into program mode because of no RFID.

I have Techstream and mini-VCI cable.

1. Ordered RFID chiplet for KEY A, installed it in key
2. Ordered second SKS key with RFID, I will call this KEY B
3. Connected 12V battery to charger to avoid rundown during 16min programming
4. IG-ON with KEY A not in slot, once car is on I inserted KEY A in slot so the RFID can be read
5. Techstream detects the VIN and I chose "w Smart Key".
6. Went to Immobilizer; Utility; Reset the Immobilizer
7. Generated code from token purchased from one of the online sources, worked, 16min later process completed.

Result:

1. KEY A will no longer start the car, SKS or in slot (and it was the key in the slot during the programming) no
2. KEY B (which was outside the car during IMMOBILIZER RESET programming) now works in slot to start the car.
3. Security Indicator Light is SOLID when car is off, blinks in error pattern 2-2 when car is on and when driving. This blinking while driving is new and annoying.

Next Action Taken:

1. In Techstream in SKS section, did Smart Key Erasure using second token, 16min process, KEY B SKS works to open doors but not start car. It will still start car if inserted into slot.
2. Did Smart Code Registration for KEY A, now both keys work to open doors, but neither key works to start car via SKS.
3. Attempted to do Immobilizer Registration with KEY B, following instructions I remove it from slot, insert it into slot, go to IG-ON, hit next, but process errors out saying "Make sure battery voltage is at least 8V and car is set to IG-ON". Car is on a 12V 6A charger in addition to a fully charged 12V batt and the car is in IG-ON.

Really puzzled and stuck! At least I have one key that will start the car, but I am worse off than when I started. Any ideas on what to try next? Maybe IMMOBILIZER RESET with KEY B which is now working to start the car when it is in the slot?

Thank you!!!

Torquewrench

References:
I have a bunch of references to the Priuschat threads I drew upon to learn enough do the above, but I'm not able to post them yet due to my status.

 

System Diagram from Repair Manual:

 

From reading the Service Manual section EI - Engine Immobilizer, the Security Indicator Light staying on when KEY B is removed indicates the Transponder ECU is in registration mode aka programming mode. This is Part A of the Chicken Dance.

With car off if I insert KEY B, the Security Indicator Light flashes with pattern 2-2, which indicates I am trying to register a key that has already been registered. Since KEY B will start the car when it is in the slot, this makes sense.

Language from the manual: "Trying to reregister an already registered key will be cause code 2-2 to be output when the key is inserted." page EI-14, see first attached image below for code 2-2.

When I insert KEY A, Security Indicator Light flashes with pattern 2-1, which indicates key code registration has failed in automatic key code registration mode.

Language from the manual: "Trying to reregister an already registered key will be cause code 2-2 to be output when the key is inserted." page EI-14, see first image below for code 2-1.

Reading further in the Service Manual, I think I have a next step (page EI-58, 59):

(b) End automatic key code registration mode.
Automatic key code registration mode can be forced
to end when at least 1 key code (immobiliser code)
for the key has been registered

(1) Turn the power switch from ON (IG) and OFF 5
times within 10 seconds using the already
registered key.
HINT:
• When no key is inserted into the key slot in
automatic key code registration mode, the
security indicator light remains on.
• When the immobilis
er

system is operating
normally and the key is pulled out, the
security indicator light blinks continuously.
• If the key code registration has failed in
automatic key code registration mode, code
2-1 will be output from the security indicator
light. Trying to reregister an already
registered key will cause code 2-2 to be
output when the key is inserted. If the
number of registered key codes exceeds the
limit, code 2-3 will be output from the
security indicator light.

I will try this and report back.

 

Thought I would post some Techstream images to make it clear what I am seeing and to help others:

 

Some progress!

Used this to exist Automatic Key Registration Mode:
(1) Turn the power switch from ON (IG) and OFF 5
times within 10 seconds using the already
registered key.

Now Security Indicator Light blinks normally when car is off, does not blink when car is IG-ON or Ready (driving)!

KEY B, which is the new key, is still the only one that will start the car. It will start the car only when inserted into the slot. Both keys will lock/unlock via SKS, but will not start car with SKS.

Now that I understand a little more, here is what I think happened to get here:

1. KEY A is the key that came with the car, will start car via SKS but will not work when inserted into slot. My theory is the previous owner replaced the shell and did not swap over the RFID.
2. I attempted to do chicken dance, but since KEY A has no RFID, I could not start it since inserting and removing KEY A from slot would have no effect.
3. Purchased RFID (4D67/ID67) chip from eBay and added it to KEY A, but since this RFID is not registered it would not yet work to allow KEY A to work in slot.
4. With car in IG-ON via KEY A SKS, in Techstream I initiated Smart Key Registration (accomplishes same thing as chicken dance Part B) and add KEY B to SKS, so I now had two keys which would work via SKS including starting the car. I believe this is because KEY A was correctly registered to the Immobiliser at some point when it did have an RFID chip, and it was able to pass this status to KEY B. Again, both keys would now start the car via SKS. Neither key would work in slot.
5. With car in IG-ON via KEY A SKS, I then put KEY A (now with RFID chip) into slot, and in Techstream I initiated Immoboliser Code Reset (using 1 token). 16 minutes elapsed successfully, but I don't believe KEY A RFID was read properly (evidence below supports this).
6. At some point I must have inserted KEY B and it's RFID was read as the Master Key, which is why it now works in slot to start the car. Neither key now works to start car via SKS.
7. Car was now in Automatic Key Code Registration mode (Security Indicator Light solid when no key inserted). When I inserted KEY B, since it was already registered I got Code 2-2 flashes, which indicates this RFID has already been registered. When I inserted KEY A I get Code 2-1 which indicates key code registration has failed in automatic key code registration mode. I'm not sure why KEY A Immobiliser Registration is failing, but the error code fits with other information.
8. Because the car was in Automatic Key Code Registration Mode, it would not enter Immobiliser Code Reset again, Transponder Registration, or Transponder Erasure (errors in images above). This now makes sense.
9. I was able to do a Smart Key Reset (using another token), took 16 minutes, completed successfully and I was able to program KEY B and KEY A. They open locks but will not start car using SKS.
10. To exit Automatic Key Code Registration Mode I used the technique from above: turn the power switch from ON (IG) and OFF 5
    times within 10 seconds using the already registered key. This successfully exited the mode.\

Next step will be to attempt Immobiliser Code Reset again.

 

Once I successfully exited Automatic Key Code Registration Mode, KEY B is FULLY FUNCTIONAL!

KEY B works to start car in slot AND works to start car via SKS and locks/unlocks doors. I can now hopefully use this to add KEY A via Chicken Dance or Techstream.

Stay tuned!

 

Ok, the issue was originally that KEY A was missing an RFID chip, and then the 4D67/ID67 RFID chip that I purchased from eBay is either non-functional or its encryption is not coded to the Toyota requirements.

From Ovni's post "UPDATE to Low Price Alternative to Prius Keys 2004 - 2009 years only" post #3: "The key is just a generic Toyota key. I inserted a chip that is coded to the same encryption as the 04-09 Prius".

So when I did Immobiliser Reset, even if KEY A was the Master Key, it could not read the RFID chip and therefore went into Automatic Key Code Registration Mode, and when I inserted KEY B which did have a working RFID chip (purchased from Amazon "Key Fob for Toyota Prius 2004 2005 2006 2007 2008 2009 Replacement Keyless Entry Remote Smart Key Fob for Silver Logo, P/N: 2584A-B31EG, 89994-47061 (FCC ID: MOZB31EG)" $60), KEY B was successfully registered with the Immobiliser.

So my options as far as I understand them are:
1. Locate an RFID chip that is coded/encrypted appropriately, perhaps from a used Prius Gen2 key from eBay.
2. Order another of the same new keys I ordered from Amazon $60, which has a working RFID chip.
3. Live with status quo: KEY B works in slot and full SKS functionality, KEY A does not work in slot but has full SKS functionality.

Option 3 is good for now, KEY A can be the backup.

I understand these systems much better now so if I can help anyone else I am glad to help. Thank you for reading!