Mau want to check the manual on that one. I dont hink it is supposed to. I know on my Sienna XLE w/immobilizer once I put the key in the ignition the light stops flashing. I believe if the light continues to flash after the key is in there may be a problem. I would have to look at my manual to be sure of that though.
Its not supposed to be flashing once the key is inserted into the ignition (that is, if you're using the right key - I assume it is if you can start the car). Maybe it depends on the specific model? I have an 05 XLE V6, and it doesn't flash after the key has been inserted.
I'd recommend checking with your dealer's service dept.
I had this same problem on a 2008 Corolla - flashing while driving, solid when not in use. The dealer fixed it - they said the car was accidentally left in "auto register mode" after I bought a key fob from them. They took it out of auto mode, and now it acts like it should - off while driving and flashing when not in use. Incidentally, I only figured it out because this problem prevented a remote start unit from starting the car.
Resolved this issue without taking car to the dealer
Had the same issue in my 2013 Corolla LE. Blinking while driving and Solid when key is removed.
Found somewhere about how to fix "Automatic Registration Mode" for Lexus without going to the dealership.
Just turn the key on and off at least 5 times within 5 seconds.
Tried this on my car and boom..Fixed the issue. Super happy
Thank you! I was driving myself nuts with this problem. I bought an orange OBDII "Key Maker" that worked fine to program one transponder key for my '06 Matrix, but left it in that "learning mode" where it was solid when off, blinking when the key is in, but started just fine with both my original and the new key. Light kept blinking when the engine ran. Flipping the key on and off 5 times quickly (within 5 seconds) made the car go into the normal security mode where it flashes when off and no key in ignition, does not flash when the programmed key is in the ignition. Now I have two working master keys.
If anyone wonders, these "Toyota Key Maker" things are about $15 on Amazon. Mine worked just fine save for remaining in learning mode. There are no proper instructions for these things, so I was flying blind.