Number of keys in ECU?

  • Hello All! I just found this forum and have a question to ask. My car is a 2001.


    Could someone pls tell me how many keys actually came with the 2000/2001 cars or if you could confirm if you have 3 keys that can start the car?


    My car came with one black key and one gray valet key when I purchased it used. I bought a Honda original key and had it cut at a locksmith. (Per my printed owners manual the car originally came with 3 keys - 2 black, 1 gray)


    I took the car to a Honda dealer and they were not able to program all three keys. They were quite certain that the car can only accept 2 keys maximum which conflicts with everything I have read. After 30 minutes in the service bay the technician confirmed that his programming machine could only add 2 keys. Of course I paid to have my 2 keys programmed back into the car!


    Any thoughts are appreciated.

  • Quote from the official handbook (MY 2000-2003):


    Page 22-117
    "System Description
    The vehicle is equipped with an immobilizer system that will disable the vehicle unless the proper ignition key is used. This system consists of a transponder located in the ignition key, an immobilizer receiver unit, an indicator light, and the ECM. ...


    When the key is inserted in the ignition switch and turned to the (II) position, the immobilizer receiver unit sends power to the transponder in the ignition key. The transponder then sends a coded signal back through the immobilizer receiver unit to the ECM.

    • The immobilizer system can store up to six key codes.
    • If it is necessary to rewrite the ECM, the dealer needs the customer's vehicle, all its master keys and valet keys, and the Honda PGM Tester equipped with an immobilizer program card with the latest version of PGM Tester software. Any key that is not learned during rewriting will no longer start the engine, except keys duplicated with the llco Code Key Duplicator.
    • If the customer has lost his key, and cannot start the engine, contact Honda Customer Relations.
    • It is possible to add ONE new key without reprogramming all of the keys (follow the prompts in the PGM TesterIMMOBI menu)"

    Hope this helps.

  • Good info!


    Also this video is helpful. Get yourself such a device and don’t get ripped off by incompetent dealers...


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    You can always resell it, or keep it for rare occasions or share it for a small fee in forums for folks who only need it once.

  • Thanks for the information from the handbook and the video. I used the information to ask the dealer for the specific error message and the type of equipment they used.


    I actually have the device mentioned in the video and have tried the procedure. Was really hoping this had worked as I wanted to do the job myself. The CK-100's 'Honda' category does not have the S2k. The 'Honda USA' category does but I was not able to connect to the ECU at all.

  • There could indeed be an incompatibility with European ECUs vs. the US versions with regards to the CK-100 functionality.


    Have you listened to the advice regarding matching the right timing, maybe one root cause, but I doubt it actually.


    In Germany, some locksmiths can program it for you for around 50€ bucks. They need all keys and and access to the car via OBD.

    The value of life can be measured by how many times your soul has been deeply stirred -


    Soichiro Honda

  • One other hint, there seems to be a difference between preface and face. So worth checking the chips you have at hand or part number thereof to be sure you have the right immobilizer key/chip.

    The value of life can be measured by how many times your soul has been deeply stirred -


    Soichiro Honda

  • Hi there
    I have also 2 keys for my S2000 from 2000, a black one (with the remote control) and a grey one.

  • My S2000 is a MY 2006 and came with only two keys from the factory.


    Alex :)

    MY 2009 came with only two keys also.

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  • Thank you all! Very interesting to get the confirmation that your cars came with 2 keys only.


    Today I got a reply from the dealer with a very different explanation from what I was told when I took the car for service (which was that the car only supports 2 keys). This new explanation makes more sense:


    "We used the Honda computer who is up to date to program your keys on your car. This one did not recognize the key you brought so it was impossible for our mechanics to program that key. The computer just recognized the two original keys of the car. The two keys were then reprogrammed with the immobilizer. The key was not bought here so we can not say what the problem is. We can only presume that there is no chip in this key, or that it has the wrong chip in it, what would explain why the computer did not recognize it. We can program up to 6 original keys."


    The key I have is an original part:


    Part No.: 35113-S84-A02
    Key, Blank (Main)(Black)(Immobilizer)



    So, as noted by @berzcheft it could be that the chip in this key is not compatible with my car.

  • I( have done a little research on the used protocol in the Honda key and came to the following conclusion:



    MY EU US
    00 MEGAMOS Fixed13 ???
    01 MEGAMOS Fixed13 MEGAMOS 48
    02 MEGAMOS Fixed13 MEGAMOS 48
    03 MEGAMOS 13 MEGAMOS 48
    04 MEGAMOS 13 MEGAMOS 48
    05 MEGAMOS 13 MEGAMOS 48
    06 MEGAMOS 8E MEGAMOS 8E
    07 MEGAMOS 8E MEGAMOS 8E
    08 MEGAMOS 8E MEGAMOS 8E
    09 MEGAMOS 8E MEGAMOS 8E



    MEGAMOS 13 is also known as TP05.
    This explains the Honda US category as it is not in line with EU vehicles.

  • Seems many of us have different amounts of keys.
    Also with my 2006 modell I got only two. I checked the purchase contract and there is also mentionend two.
    But they are different, one black with one side ornament and one simple grey. But both with remote control. See attached pic for comparison.


    My first thought was the grey one is not opening the locked gloves box. But it has full funcionality - checked.


    Because with my 2003 Accord I got three keys, two "full" and one as a so called mechanic's key, not opening the gloves box.
    My 2008 CTR has also two "full" keys only.
    Anyway for me two keys are good to survive


    As Alex got two keys only as well - we have same years - I am wondering if Honda started cost savings during the course of production somewhen.

  • Great information.


    This I think explains the issue. The key I bought (35113-S84-A02) is not compatible with European ECU's.