Transponder key won't program

It sounds right. I had the dealer program our backup key so I've not had a chance to practice the procedure. I did replace the FOB on my own.

Bob Wilson

 

It's possible that you got the wrong transponder key. It's probably a type 4C transponder, and there are several type 4D transponder keys used by Toyota. Google any numbers you find on the key, along with the key manufacturer's name.

There are locksmiths who have the equipment to clone the key you already have. A clone key looks exactly like the original key to the car, and thus the car does not have to be programmed for the clone key. The biggest project will be finding a locksmith with the proper equipment.

The only difference between the black and grey keys is cosmetic. The functional difference is established by the programming of the car, and the cut on the key. An original black one is a master, and can be used to authorize programming another key. The original grey key cannot be used to authorize programming another key. If your black key was programmed as a valet key, then that would explain why you can't use it to authorize another key.

 

Funny, I was told by a Toyota technician that the only way to program keys on this vehicle was to use a Toyota scan-tool. Perhaps he was unaware of the procedure listed above. Since I too and in need of a second key, I may be trying this myself.

 

Check the Yahoo group "Prius Technical Stuff" archives. I saw something about this there.

Bob Wilson

 

hello,

when i tried to do the same things with the instruction you wrote it didn't work too.

i found full instruction on coasteltech.
it tells that for sub-keys programming on the step 4 you should open and close door only 5 times not 6.

whoooa and it helps!

don't forget about step 8, before testing the new key.
good luck.

а.

 

It's good to hear that you have a solution. Thanks for the report.

The battery for a clone key is a new one on me. I've got a clone key that doesn't use a battery. It cost about the same, and was produced with a Jet brand transponder duplicator.

If you're up to more work on this issue, one thing you could do is to install a universal transponder bypass unit. They are generally used with aftermarket remote start and burglar alarm systems. You put a transponder key inside the box, and a wire back to the antenna around the ignition switch. When power is applied to the bypass unit, it relays information between the transponder and the antenna at the ignition switch. If you just power the bypass unit from the switched 12V system, it will appear that the transponder is present anytime the car is turned on. The ignition security reverts back to just the cut of the key, like all cars used to be. Then you can buy all the $2 keys you want. I paid something like $20 for a bypass unit.

 

Transponder key won't program (4c or 4d) ?

Confused here, does the 2001 to 2003 Prius, use a 4c or a 4d transponder key? None of my original keys from Toyota, have any numbers on them.

 

Re: Transponder key won't program (4c or 4d) ?

I think the 2001-2003 has a 4C but there is nothing on the key that identifies it that way. There are at least 3 keys that use the same blade as the 2001-2003 Prius. They are the 4C, 4D, and non-transponder versions. To select a key blank to use with the Prius, just use the car name and year to identify it.

 

An original black one is a master, and can be used to authorize programming another key. The original grey key cannot be used to authorize programming another key. [/QUOTE]
That was my problem. I was using the grey key. Switching to the black one did the trick. Thanks!

 

Well, kind of yes, it's in the manual. The reason I say "kind of" is: There's a physical cut called master (it opens all the doors and the trunk), and a physical cut called valet (it doesn't open the trunk). There's a way the key can be programmed called master (can be used to program other keys), and a way it can be programmed called sub (works, but not authorized to program other keys).

When Toyota sold the brand new car, the black keys were cut as masters and programmed as masters, and the gray ones were cut as valet and programmed as sub. What you get with a used car could be anything, because a key of any color can be cut either way and programmed either way. (It's hard to change the cut later, but the programming can be changed any time.) And the key blanks I was finding on line were pretty much all black, so whichever way you cut or program them, they'll still be black.

The way you tell master (cut) from valet is by seeing whether it will open the trunk. The way you tell master (programming) from sub is by watching how the security light blinks when you insert the key.

These questions do come up from time to time, so to save later readers the endless rediscovery of Westheimer's Discovery it might be worth linking to older PriusChat history where they were already covered.

As always, you can find as many guides for how to program the keys as there are cat jokes on the internet. In the spirit of Westheimer, you can try them all to see which ones work, or you can drop by techinfo.toyota.com and compare them to the ones in the manual. The ones that are the same are the ones that'll work. The ones that aren't, won't.

Or you can save the time of searching and start with the ones that work.

-Chap