SKS (Smart Key) Trouble; Hybrid Immobilizer Light

how is the 12v health?

 

doesn't seem too bad, but not sure how much draw accessory mode applies.

 

THIS IS ALL YOU HAD TO STATE, especially text highlighted in blue.

Something caused the SKS function to stop working correctly, as observed with the re-found "master" and machine washed FOB. What was this event, if you can recall? This is the source of your problems. The 12V and FOB battery were strong enough, for the SKS to function correctly, prior to the mysterious event. Was your car in an accident? Was you car in a flood?

EDUCATION TIME:
Gen1 (1997-2003) uses a MASTER key and uses a MASTER designation for programing additional keys.
Gen2 (2004-2009) Prius does not have, or use, a Master/Slave FOB designation.
As long as you have a 100% functioning Gen2 FOB (all functions work), you can program a 100% new, virgin, FOB for Gen2 by yourself.

Read the SKS section in your Owners Manual; it explains it OK, not well.

SKS Prius has "Oscilators" (think antenna) looking for correct KEY ID and VEHICLE ID transmitted by SKS fob:

Exterior oscilators- front doors (Right and Left), rear hatch,
Interior oscilators: center console (covers front), left rear quarter panel (covers rear)​

Each SKS fob has a KEY ID and VEHICLE ID, "burnred" onto the SKS fob motherboard by the vehicle's CERTIFICATION ECU (brains of SKS).

• The SKS fob transmits these two pieces of info with a working fob battery. When in range of your SKS Prius, you will be able to enter and start your vehicle without ever reaching for your SKS fob.
• KEY ID and VEHICLE ID are unique to your SKS Prius, and created by the CERTIFICATION ECU, which was set at the factory.
• This is why 100% new, virgin SKS fobs are required to have 100% SKS functionality.
• When a used SKS fob is attempted to mate to an SKS car, the used SKS fob will only be able to function as a dumb fob (manually insert into fob slot every time). The used SKS fob already has a KEY ID and VEHICLE ID "burned" onto the SKS motherboard, that is not recognized/authorized by the Prius to work in SKS mode. Defeats purpose and convenience of SKS.
• 100% new, virgin SKS fobs are a little bit more than used SKS fobs on crapBay(eBay) and Amazon.
• When all original or the last working SKS Fob is lost, dealer intervention is required. A pricey rest (clear all authorized fobs from memory) and reseed (add fobs) will need to be done.
• Supposedly, used SKS fob can be made to function correctly, but requires dealer intervention (reset/reseed). Given the cost of dealer labor, and the small cost difference of new vs used SKS fob, new SKS fob is the way to go.
• A used SKS fob can work correctly on a non-SKS Prius, for obvious reasons; no SKS in the car.
• Maximum number of Fob (SKS or non-SKS) a Gen2 Prius can be programed with is 4, IIRC (if I recall correctly). Two spots are occupied by the original two Fobs that came with the new car. There are only 2 more slots left.

END OF CLASS.


1) You CAN NOT program/reprogram your current SKS Fobs, b/c they are already programmed to your car.
2) In post #7, you state

BE SPECIFIC. Your descriptions are vague, and do not help with diagnosis.

Is the spare SKS fob the long lost "refound" SKS fob or the machine washed SKS fob?
What do you mean by fixed?

Is every function of the SKS Fob working?

SKS functions works completely: lock/unlock via small black button on both exterior door handles.
Trunk can be opened via small black button on trunk.
Able to Start the car via SKS, w/o ever inserting SKS Fob into dash FOB slot.
With SKS dash button depressed to deactivate SKS, able to start the car with SKS Fob in dash slot?
Remote buttons on SKS Fob works completely:

lock all doors,
unlock drivers door (1-time unlock tap),
unlock remaining doors (2nd unlock tap),
alarm button​

3) Since SKS Fobs have a motherboard inside, it could be possible for the motherboard to go bad, completely or partially. This could account for one SKS Fob (assumed) working, and the other not working.
4) It could even be an ECU issue for the entire SKS system. Maybe an ECU or two is bad. Maybe an ECU is experiencing intermittent operability? Hope the latter is not the case.
5) You will likely have to get dealer service to do a reset/ressed.

*You have their labor cost of $135. Ask for a discount: student, military, fire, police, student, AAA/Costco/AmEx member, etc.
*Buy two 100% new, virgin, SKS Fobs from Camelback Toyota; Don't know if both are SKS, or maybe 1 is a retired SKS part #, or the cheaper price might be non-SKS fob.

Fob part number: 89994-47061 is $156.07
Fob part number: 89904-47011 is $131.69
Camelback Toyota Webiste: 2007 Toyota Prius Parts - Camelback Toyota Parts - Genuine OEM Parts - Free Shipping
Free shipping on $150+. Likely to still have no sales tax, unless shipped w/in Arizona.​

 

Make sure the "guts" includes the RFID chip that resides at the front of the bottom half of the fob. It is a dark coloured rectangular shaped what looks like plastic with one of the corners cut off. Make sure your testing includes starting with the fob in the key slot, which confirms the RFID chip is working.

 

OK, Now I have a strange question: Why / What is the "RFID chip that resides at the front of the bottom half of the fob" ?

My 2006 Prius Key FOB does NOT have this small piece - only a printed circuit board.
Yet the Prius remotely opens the doors as I approach and the Car starts (usually).

So if that piece is vital - why is my Key FOB working without it ?

 

The other two systems you mentioned run off the PCB so as you have observed, as long as there is a working CR2032 battery installed they work just fine.

The RFID is there as a failsafe in the event your fob battery goes flat. It runs off inductive power, just like contactless credit and transit cards do.

What this means is if your fob battery goes flat, you can open the car with the mechanical key, insert the fob into the key slot and start the car.

With the RFID chip missing from your fob, you do not have this failsafe, so your car will not start with the fob in the slot. So, you better make sure you can always have or get access to a new CR2032 button battery.

 

Thanks, that clarifies it beautifully.
So the RFID is a backup to the "motherboard" PCB in the FOB.

The guy trying to sell me his $420 key solution insisted that the RFID portion was essential.
But then he was speaking Mexican Spanish - which is not my forte.
Nevertheless, I think i understood him well enough.
But he didn't want to understand when I showed him the dash lights
would recognize the key when it was close - and not when it was out of the slot.

Since my Key FOB never had that RFID piece, can I buy it separately ?
Or does it need to be Keyed to my Car (ECU, VIN etc.) ?

Anyway, thanks for clarifying.

PS Hey, I see you are in Wellington, I just drove 5,000 ks on your South Island.
Spectacular. Even had a thrilling swim with Dolphins. Sorry I didn't get to see
your fair ville. Three Cheers.

 

I guess if you are trying to pair it to the car, it is essential for it to be present. I don't know if it prevents setting up the remote lock/unlock and SKS, though.

No worries.

Yes, Te Wai Pounamu (the South Island) is spectacular and well worth seeing. I think you got the better deal if scenery is what you were after. Te Ika a Maui (the North Island) is quite different and more populated. I'm glad you enjoyed your time here.