I have a 2007 Honda Accord EX-L Automatic transmission, that I got cheap as a project car. When I got it, the engine ran fine, however it was left at a rural property for about a year and some clueless thief, not knowing anything about modern car security, decided to try to wreck the ignition with a chisel and attempt to start the car :(. Knowing that the car computer will only start upon successful authentication of the RFID chip in the key, I bought a new ignition switch & key set from eBay and transferred the chip in the old key to the new key. Now, when I turn the key the engine cranks, but will not start because the security light keeps flashing :(. Also, now the stereo asks for a security code - from my research this is completely separate from the engine starting, so not my current concern.

First, why didn't this work? Is there something else I'm missing, like a chip in the ignition switch? I have the old one, but it's destroyed. Honda wants me to get the car towed to the dealer, but that's 50 miles away up in the country, so I really don't want to have it towed. Is there anything else I can do now?



  • This sounds like you need to get the chip re-programmed to the car as a minimum. Or completely reset the security controls using the dealer level diagnostic computer.
    – Solar Mike
    Mar 16, 2019 at 2:00
  • @SolarMike I've considered that, but I'm trying to rule out all other issues before I deal with the Honda dealer some more or pay an auto locksmith to program it. I mean it just doesn't make sense to me that it won't start if I have the chip that is authenticated in the cars computer. I thought all I did was replace the mechanical lock :/. How could I check if the RFID reader is bad?
    – sharkByte
    Mar 16, 2019 at 3:35
  • 1
    When you moved the chip from the old to the new key you allowwd it to power down so it lost that identity .... now it needs re-coding...
    – Solar Mike
    Mar 16, 2019 at 5:08
  • @SolarMike What do you mean powered down? From my limited understanding of RFID, the RF energy sent to the chip is what powers it. The chip in the key does not have any power source; when you plug the key into the ignition, the ignition sends an RF signal to the chip in the key and then reads the response signal, right?
    – sharkByte
    Mar 16, 2019 at 5:26
  • If the key has buttons for locking and unlocking the car it may not be rfid...
    – Solar Mike
    Mar 16, 2019 at 5:28

1 Answer 1


OK, so I got in contact with Honda. One guy told me to tow it to the dealership, as I expected it :(, but I got really lucky and got an email from another guy who told me why this didn't work and how to fix it :).

It turns out this didn't work because I didn't transfer the old transponder reader - the black little box attached to the finishing ring where you stick the key. My assumption that it just transmits the RFID code to the computer was wrong - I guess it has its own ID that needs to be matched with the computer. I still don't see how this increases security since the key needs to be matched with the computer anyways, but I'm glad I got an answer and I hope this helps someone.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .