SKS Fobs only work wirelessly

Did you just buy the car, and this is how it has been since day one?

Were the fobs working correctly before, then suddenly stopped?

Is the battery in each remote, good?

Bizzare.

 

I believe if the fob case is replaced there is a separate part for that which must be transferred too. If it was not moved to the new case, you could have those symptoms.
The only solution would be a new fob if I am correct.

 

That's right.

There is a small RFID chip in the case; even black in color IIRC, so hard to see, easy to dismiss as part of old case. People who replace thir case, often transfer the motherboard, thinking all is done. Then they have OP'S (original poster's problem). If you indeed got new cases, find you old case and transfer the small RFID chip to the new case.

 

What made you decide to insert the fob into the dash fob slot now?

Since you tossed the original cases away, your only option is pricey b/c it would require a reset and reseed from the dealer, to regain fob slot functionality.
1) Buy two used SKS Fobs from crapBay (eBay), Craigslist, or Amazon. Not recommended since some sellers charge close to the cost of a 100% new, virgin, SKS fob. Besides, the used fob may develop problems soon after, b/c it is used; the buttons could be close to their expected cycle rate, and cease to function.
2) Buy two 100% NEW virgin SKS Fobs from a Toyota dealer who sells online. Try Camelback Toyota, $156, 2007 Toyota Prius Parts - Camelback Toyota Parts - Genuine OEM Parts - Free Shipping Pretty sure this is the SKS fob part number. You will have to verify by communication with the dealer.

You may want to consider doing this, b/c the fob slot is a fail safe way to make the car READY. Something could go wrong with the SKS portion. If this were to happen, your only means to make the car READY is via the fob slot, which is not available to you b/c your current fob cases do not have the recognized RFID chips to start the car.

 

FOB case opened.



FOB motherboard and RFID Chip.



Images courtesy of: DIY Toyota Prius Key Fob: 3 Steps
Author wrote a simple three step Fob case replacement procedure.

 

Wait a moment here.
Does the system NOT read the RFID chip every time the vehicle is started "normally" ?
Otherwise how would it know if the FOB is in the vicinity ?

 

Two systems. The circuit board handles the keypress and proximity system. The transponder (rfid) is an entirely separate system that works in the absence of the circuit board.

As a backup, I have a transponder chip mounted in an ordinary transponder mechanical key. It is stored inside the car in case I can't find a keyfob. Inserting the transponder mechanical key into the keyslot backwards works. Even if someone finds the key, I doubt they would understand how to use it...

Note that the transponder in a keyfob system is only used in Gen2 (2004-2009) vehicles. Later vehicles only have the circuit board inside the fob case.

 

Excellent post.
So that means that post '09 models need a good battery in the FOB to be able to start the car ??

 

No. They apparently can draw enough power inductively from a coil next to the Power button. Rather like the new wireless charging systems for your cellphone.

You could remove the battery from a 2010+ keyfob and store the keyfob inside the car as an emergency key. It would only work when placed next to the Power button. Or put just the circuit board in another container that doesn't look like a keyfob.

 

This is for Gen2 (2004-2009).

Yes, the FOB slot requires the RFID chip. It is considered failsafe, b/c it doesn't require a working fob battery, and there is always the possibility that the fob SKS motherboard could become inoperable/damaged/dead.

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 makes sense.
• A used SKS fob can work correctly on a non-SKS Prius, for obvious reasons; no SKS in the car, and that is what the owner has always been doing. Button press of fob to remotely lock/unlock, and insert fob into dash to READY(start) the car.

 

You stated

• A used SKS fob can work correctly on a non-SKS Prius, for obvious reasons; no SKS in the car, and that is what the owner has always been doing. Button press of fob to remotely lock/unlock, and insert fob into dash to READY(start) the car.

I would love to get my used SKS fob (eBay purchase) to work correctly on my non-SKS Prius...

I was able to easily use "chicken dance" to get the used SKS fob registered with the Immobiliser so that it can start the car via the ignition slot.

However, I still have not found a way (even using TechStream software) to get Wireless registration (the remote locking/unlocking) of the SKS fob.

After loading a brand new CR2032 battery (measured=3.30V), I tried to register the SKS fob using the Utility Selection menu of ECU=Body:

Neither of the Utilities: "Wireless Code Erasure" or "Wireless Code Registration" recognizes when I press the buttons on the SKS fob, as instructed by the TechStream procedure. Yet, both of these Utilities recognize button depressions of my non-SKS fob.

Any ideas ???

 

The wireless protocol is different between SKS and Non-SKS fobs. The immobilizer is the same, which is why the plug-in-the-dash works. No way to make the buttons work on the wrong type vehicle.[/QUOTE]

 

Dear RobH,

After receiving your REPLY, I purchased a used OEM non-SKS fob (on eBay) as a SPARE FOB for my non-SKS Prius...

Once again, I was able to easily use "chicken dance" to get this SPARE FOB registered with the Immobiliser so that it can start the car via the ignition slot.

However, I still have not found a way (even using TechStream software) to get Wireless registration (the remote locking/unlocking) of this SPARE FOB.

After loading a brand new CR2032 battery (measured=3.30V), I tried to register this SPARE FOB using the Utility Selection menu of ECU=Body:

Neither of the Utilities: "Wireless Code Erasure" or "Wireless Code Registration" recognizes when I press the buttons on the SPARE FOB, as instructed by the TechStream procedure. Yet, both of these Utilities recognize button depressions of my primary non-SKS fob.

Any ideas ???

 

Check that the red LED lights up when you press a button. A used fob could be defective, or maybe just the rubber membrane is jammed. Or a really remote possibility is that somebody switched a black sliding cover for the silver one that matches the circuit board. It's not the paint on the outside, it's the circuit board inside...

To check out the circuit board, open the case and see if you can register the bare circuit board without the rubber in the way. Be sure to hold the battery in place since the case isn't doing it. If this works, then buy a replacement case at Amazon or eBay.

Since a GEN2 keyfob is glued together, it has to be pried apart. Take out the mechanical key and battery. Then use some needle nose pliers inserted into the mechanical keyslot to spread the case open.

Use Techstream to verify that there aren't too many keyfobs already registered. I think the GEN2 limit is 5.

 

My SKS fob #1 was really bad; one button was completely gone and the front around the other two buttons was cracked enough the circuit board was visible. Afraid it was going to fail, I decided to replace the plastic case before it did. Cost me all of $9.99 from Amazon.

It was a bit of a struggle to get the original apart as I was afraid of damaging something vital in the process. Once it was apart it was a piece of cake to transfer the circuit board and that additional black chip. I was very pleased to find both the old silver Toyota logo piece and the old metal key fit to the new case perfectly. The new case even came with new screws for the battery cover and it snaps together so no glue is necessary. After assembly I went out and tested it tonight. It worked perfectly.

As part of the same Amazon order a silicone sleeve to protect the new fob is arriving from a different warehouse this coming week. I'm a happy camper.

 

Remove the magnet from the old one

Posted via the PriusChat mobile app.

 

What magnet? You mean the RFID chip?

 

Yes

Posted via the PriusChat mobile app.