I just bought a new Honda Civic this past weekend. It has Smart Entry. However, I may have made a mistake. They could only find 1 key for the car. They said they would find my key after the "keymaster" came back from vacation on Tues.

Out of good faith, I believed them. I stupidly drove home from the dealership, with the promise of my key being available later. I came in to the dealership today but my key was still not found.

After telling my friends about my experience, they said I was foolish because of a number of bad things someone could do with the key:

  1. We don't know if someone stole the key
  2. If it was really misplaced
  3. Someone took it to copy it and will come back later to steal my car or items from my car later, etc.

If they still can't find the key, I found a link (from 2009) that said the dealer could delete the missing key from the ECU and make me a new one. It also said they could reprogram the keys/car so the stolen key presumably can't be used.

Since this is 8 yrs later, is this still true? That we can delete keys from the car or reprogram the key/car?

UPDATE: Thanks for all the answers. The dealer said they would provide a free new key if the key was truly lost but thank you for your answers. You brought up other things I didn't think about.

  • 1
    It's absolutely still true, you may even be able to do it yourself.
    – GdD
    Jan 3, 2018 at 9:16

2 Answers 2


One thing you also need to consider is that the outdoor locks of the car can be manually opened without the electronic system, using the mechanical key. This cannot be fixed without changing the mechanical locks. So I would advise you to not leave high-value possessions in your car if there's any chance whoever has the key could track you down.

As for the electronic part of the key, the key can be disabled and replaced with another key. Sure, it'll cost some, but in general it's good idea to have two functioning keys for your car. Disabling the electronic key means that the car itself cannot be stolen.


All three points you make could be true.

Any good automotive locksmith, electrician, dealer or diagnostic specialist will be able to disable any other keys that may be programmed to your car that you don't have in your possession.

The only problem with this is that the car/ecu needs a minimum of two keys to be programmed so if you only have one you need to buy another spare key. There is one way to overcome this by manually editing the memory contents of the ecu/immobiliser module and entering 'dummy code' into the area that holds the info for the second key, this is a very specialist job which can only usually be done by a very good tuner or auto electrician.

So in summary: Buy a second key and have it reprogrammed and at the same time have them disable all other keys.

Speek to a specialist, tuner or auto electrician to see if they can disable the second key through the ECU without having a second key.

  • Seems like the Honda dealer would be the one and only shop to seek out, right? If it's a very specialist job, let the dealer do it - you know they have the tools and knowledge.
    – JPhi1618
    Jan 3, 2018 at 14:42
  • I would rather use a auto locksmith or electrician, they would have far more knowledge than the dealers and would probably be cheaper to. Its only a specialist job if you try to disable the second key without programming another. It's quite simple for someone with the right kit, either way find a good independent person/company Jan 3, 2018 at 18:23

You must log in to answer this question.

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