Question about adding another key and fob

[CTScott]

Originally Posted by rcvmini

CTscott upon further reading I think it is because once a master key is registered with the car with tthat procedure once any key added after needs the tool to program it.

At 16 bucks I think the eBay tool might be worth a shot. I only have to figure out what a 4D and 4C key are. On another site people have reported it worked for an fjcruser and some other cars

Correct on the master key part. With a new ECM that has no keys programmed you can add the first key without TechStream.

I have never heard the 4C and 4D terms, but looking at some of the sites that sell blanks, the Yaris is listed as using 4D.