Toyota Corolla Immobilizer

We have heard a lot of customer complaints about the built in immobilizer on the 2005 – 2008 Toyota Corolla, being the most common complaints; “The car cranks OK, but won’t start” or “The car cranks and starts, but the engine die in about a second”.

The problem in most of the cases is caused by the immobilizer system, either by a malfunction or by a code mismatch between the key and the ECM.

The immobilizer is an anti-theft system implemented on many modern cars and it is integrated by (1) the ECM, (2) the car keys (called “transponder keys”), (3) a coil antenna mounted around and inside the key lock assembly for communicating with the key internal circuit and in some models, (4) the transponder ECU, which processes signals of this system. This last one is not always included. In some models, the job is done in the ECM and there is no transponder ECU present.

Inside your car key’s plastic handle, there is a micro chip in a glass or plastic capsule which contains the whole circuit needed for the key to transmit an unique code when it is close to the energized coil antenna inside the key lock. That is why the key’s handle is wider than normal.

Many crystal transponder chips:

The circuit inside the key needs no battery, as it is powered up by inductance by the magnetic signal coming out from the coil antenna. Right after the key is energized by the antenna signal, it transmits a response to the coil with the code it has stored in its internal memory. All the communication and power feeding between the car key and the transponder system is electro-magnetic.

Transponder antenna (inside key lock cylinder):

The code received by the coil antenna from the car key, is amplified and decoded by the transponder circuit and then transmitted to the ECM to be compared with the code already stored on its memory. If the comparison tests Ok, then the transponder circuit sends a signal to the ecu to allow the engine to run. Otherwise, the ECM will not send any signal to the injectors and igniters.

There are several cases where you may have some trouble with the immobilizer.

1. In the event that the owner loose a key, he or she can order a blank key, have it cut and programmed by a locksmith by using a key cloning equipment.

2. If all keys are lost, then the ECM must be reprogrammed (sometimes erroneously called flashing or reflashing) to accept new keys from zero.

Toyota Corolla immobilizer reset service:

3. If the ECM is replaced by an used ECM, the keys in the used ECM memory will not match the keys you have and the engine won’t start. The solution in #2 above will work flawlessly, but in this case, you may try doing an immobilizer synchronization to match the incoming ECM to the immobilizer system of your car before you invest any money and time on this. The solution is below, but if it does not work, as sometimes it does not for no reason, then the solution #2 above will always work instantly.

Toyota synchronization

To sync your replacement ECM, you will need to jump two wires in the diagnostic connector for 30 minutes, with the key in “ON” position, that is, all the way forward right before starting the engine. because of this, you will need to make sure that car battery is charged completely or you may do the sync with a charger connected to the battery to ensure that voltage will not drop. If voltage drops too much, the whole process must be restarted and the 30 minutes wait will need to be waited up again from zero.

Toyota synch procedure:

Important: If using the service in solution #2, please note that the VIN number will be erased as a normal automatic process, done internally by the ECM after clearing or resetting the immobilizer data. It can not be avoided if resetting the immobilizer, but it will cause no performance problems or problems of any kind, except for having the check engine light on, indicating that the VIN number is missing. The VIN can be entered by bringing the car to a Toyota dealer or any independent shop that has the equipment to do so. It can be done with any J2534 capable scanner or device, with the Toyota VIN update software.

What other users are looking for:

[toyota immobilizer reset]  [toyota corolla security system reset]  [https://qcwo com/technicaldomain/toyota-corolla-immobilizer/]  [toyota avanza immobilizer problem]  [toyota 2009 yaris keyless program with immobilizer]  

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28 Responses

  1. Andrea Bailes says:

    It was interesting to find this article as I just recently purchased a used 2006 corolla and was only given one master key. This is the only key I have for this car and they did not give me the code. Can a dealer still make another master for me (using the one I have) even if I don’t have the code?

  2. admin says:

    Hello Andrea. Thanks for writing.

    Yes, the dealer should be able to make a new key with your master and the car’s VIN number. The problem for the dealer is when the master key is lost.

    The VIN number of the car, the pin number (seed) and key codes are stored in the ecu (car computer). In case that the master key is lost, then the ecu must be reset (as explained in the article above) for it to learn new keys.

  3. Daniel Soto says:

    I just received the Toyota ecu you serviced this week. Now it works fine with my keys. Just wanted to thank you. I saved a lot as the dealer quoted a lot of $$$. About the issue that we were talking about, with the check engine because of the VIN number, I went to the dealer and they set it for free as you adviced to do. I will promote your service (as I am doing now) here in my area. Thank you very much!

  4. admin says:

    I am glad you brought your car back to life. It was a pleasure helping you.


  5. Jan says:

    My father bought a Toyota Corolla 2006 S model two years ago from US. He got only one master key with remote controller.
    He´s living at Slovakia and wants to make an duplicate key but our dealer of Toyota said him that they have no software for programing of this key which is needed for Toyota from US. Because cars from US market are different than cars from European market. Further more at Toyota Slovakia they told him “there is exists some instructions for self-programming of this key.” Could you advice me if instructions like this does exist or what can he do when he wants to get this key.

    P.S. if it is possible to self-program the key and u have the instrustions could u send me them. Thank you


  6. admin says:

    Hello Jan.

    About the keys from USA being different from the European ones is true. Codes change.

    About programming a new key, it is easy and simple, provided that you have (1) an USA key of your model and (2) the key is blank and unused.

    You can do this procedure either before or after mechanically cutting the key.

    You might want to revise and practice the procedure before actually doing it, as it have a few steps that each one have a specific time frame.

    It is a s follows:

    1 Take the master key you have and insert it into the ignition switch. The master key should be black colored, not grey.

    2 Turn the key to on position and before 15 seconds, press and release the accelerator pedal for exactly 5 times.

    3 Now, before 20 seconds, press and release brake pedal for exactly 6 times.

    4 At this time you can remove the master key and within 10 seconds, you must insert the new black key to be programmed into the ignition switch.

    5 Next, before 10 seconds, press and release the accelerator pedal just once.

    6 Wait a few seconds, then remove the new programmed master key.

    If you want to program another new key, you must insert it in the ignition cylinder within 10 seconds after the above procedure and press and release the accelerator pedal only once and wait a few seconds before removing it.

    Test all the keys you programmed after finishing.

    You can program up to 7 keys using this method. After that, the ecu must be cleared to accept new keys.

    Best regards.

  7. Jan says:

    Hi admin.

    Thank u for your response a for the instructions. That is the matter what I want to ask you.
    I found some instructions before you sent me yours on

    Add Duplicate Key:

    1. Simultaneously depress and release brake and accelerator pedals 1 time.

    2. Insert existing master key into ignition. Do not turn the key from the OFF (LOCK) position.

    3. Within 15 seconds of inserting the key, depress and release the accelerator pedal five times.

    4. Within 20 seconds of completing the above step, depress and release the brake pedal six times and
    remove the key.

    5. Within 10 seconds, insert the new key into the ignition.

    6. Within 10 seconds, depress and release the accelerator pedal one time.

    7. After 80 seconds the new key is registered and the security light will go off.

    8. Remove new key and depress and release the brake pedal 1 time.

    Steps 2-7 are completly the same like yours steps (1-6). But step 2 (in my instructions) is different in position of master key.

    So which position of master key is correct and should be done the steps 1 and 8 (in my instruction) as well? Because my father already did whole process according to steps above but nothing happend and master key was in OFF(LOCK) position.

    And secondly: I was reading on forum of toyota that during the self-programing can program get frozen and ecu have to be replace. Is that right???

    P.S. I hope that your instructions will be work.

  8. admin says:

    Jan, we have done it with the key in accessory/radio, not on ignition position, so I guess that for the process being taking place, it will be the same as ignition circuits will be powered off. Depressing both pedals might be some type of reset before entering the programming/erasing mode. Ours, worked OK without that step.

    I recommend that you first try the all key erasing method, as you only have one key, then do the steps to try to program the new one.

    If still nothing happens after trying both instructions (here and the mentioned site), then it might be the case that (1) the key being tried to program is not compatible with the transponder on your car or (2) for some unknown reason, your ecu is not accepting any more keys even after the process of erasing all keys.

    It is important to notice the flashes of the security lamp, as per the instructions in the site you posted above, as a guide for knowing if the process is being working. If for some reason it doesn’t flash as expected, something is wrong, either with the ecu or the new key.

    I assume that the car is working with the unique key you have, so I rule out the rest of the circuits like the ring antenna and the key lock transponder circuit.

    About dealers, they usually replace the ecu if they don’t have the equipment for resetting the ecu. We do reset the ecu with an eeprom programmer and the correct file for writing on the security chip, which is located in the ecu circuit. A little bit of a technical job.

  9. darwinl eal says:

    buen dia ya veo que tienen amplia experiencia com la materia y queria pedirles asesoria.tengo un toyota corolla 2006 y suplante la ecu el inmo y las llaves todo nuevo de caja. programe las llaves y todo bien el carro prendio perfecto. pero tengo un codigo p0630 que me dice que el vin no ha sido programado .cual es el procedimiento para este caso y como se realiza con el tester inteligente gracias..

  10. Richard says:

    Hello Darwinl.

    That will always happen when you replace the Corolla ecu for a new one. The new ecu does not have the VIN number on its memory, so it will have to be entered on a certified dealer or using a Toyota specific application with the capability of entering the VIN number, like Techstream. That’s a common issue when replacing the ecu, but there is no malfunction at all.

    If you don’t do it right away, don’t worry, as the check engine light and P0630 will be all to it. Apart from that, all systems, including the immobilizer will be working ok. You won’t have any problem. When you have any spare time, you can go to a dealer near you to enter the VIN number. In some dealers it is a free job, while in some others they will charge a small fee about $40.00 – $50.00. It will all depend on the dealer, but it is a 15 minutes job.

    Best regards,


  11. KABELO says:

    I had immobiliser in my 96 corolla 4afe removed,it was starting okay for a while now the ecu light does not go on and the car just cranks but won’t start.What could have gone wrong?The ecu looks ok, Somebody please help,I’m at wits end

  12. Guest says:

    Hello Kabelo.

    Thank you for writing 🙂

    After the immobilizer was removed, for how much time did it start ok before the ECU light went on and stopped starting?

    I wonder how did the immobilizer was removed. In all Toyota models I have seen, the immobilizer can be reset or can be reprogrammed, so it does not look for transponder keys, but it is never completely removed. There is always a code working on the immo chip.

    If it was the second option above, then the key amplifier (ring antenna circuit in the key cylinder) must be disconnected and if a separate immobilizer box, known as immobox or transponder ecu, it must also be disconnected.

    I reprogrammed once a 1998 Toyota Camry so it does not look for transponder keys and it worked fine the whole day. Next morning, it did not want to start. After the key antenna amplifier was disconnected, everything was working fine again. In this case, the immobox was not present.

  13. soon jung says:

    thank you very helpful,but my car 2005 corolla ce does not set alarm,neither security light flashes or stay on when not set(disarm)it is off,please sr our family need your expertise

  14. martin says:

    changed my starter motor on my 1998 corolla but the problem was a worn barrel so got new set from brakers ie immobleiser key barrel now car will not read turns on but will not fire

  15. Mace AP says:

    Just replaced ECU(used)on 02 Corolla Runx,engine cranks but doesn’t start, security light flashes, can anyone please help, How can i bypass the immobilizer to kill the security feature so it wont search for the transpondent key.

    many thanks for any assistance.

  16. Guest says:

    You will need the ECM to someone that can reprogram the ECM to accept the keys. A Toyota dealer should be able to do it.

    One thing you may try your self is a trick for synchronizing the used ECM with the key codes in the immobilizer system. The picture below describes it. Take in account that the vehicle battery must be fully charged or connected to a boost charger, because the process takes almost half an hour with the car switched to “run” position and the engine off, which will drain a weak battery. If the process is interrupted even slightly because of low battery, it must be started over and wait 30 minutes more again. So please make sure about battery charge.



    Toyota immobilizer key synchronization process

  17. Jason Gallardo says:

    Regarding this issue, I have something that’s a variation to this issue….my wife’s friend has a 05 Corolla that has a
    intermittent starting issue.
    -key in ignition (black key)all lights work, radio, ect. but motor will NOT crank at all, lights do not dim, so it’s not a Battery or Alternator issue as their family mechanic said the electrical system checks out perfectly.
    She had heard to cycle the Key On Key Off 5 times and it would work and still is intermitten, can you help?

  18. Guest says:

    Hello Jason.

    Does the car has an alarm that cuts starter? That is mostly the problem in these cases, as the immobilizer disables ignition and injection, but do not disable the starter at all. With the immobilizer set, the car will crank until depleting the car’s battery, but the engine will not start.

    Your problem must be in an aftermarket security system (alarm) that could be installed in the car or in the starting circuit wiring per se.

    If the security system is the case, try resetting it. If that does not work, you should search for defective components in that system.

    If no security system, then you should check the starting circuit components with the provided diagram in the link below. It is composed of the starter itself, some relays, some fuses, its wiring and the ignition switch, which reminds me, that a defective ignition switch tends to do that problem too.

    I hope this helps,



    2005 Toyota Corolla Starting Diagram:

  19. Jason Gallardo says:

    ok Richard, I have some more info from last night and her car.
    It does in fact have a Factory Installed Toyota alarm.

    She said that when the corolla decides it’s not going to start:
    – all the lights, radio work
    – when she turns the key, NOTHING happens as in: No engine rotation, no lights dimming.

    AAA tow truck driver shows up and she says “he tapped on something right above the starter” and the car started, so he left….as I was driving home the car completely shut off and I called AAA again and they towed me home. Same issue as all the lights and radio worked, but the motor wouldn’t rotate when I turned the key”

    In my honest opinion, regardless of what their mechanic had said about the electrical being 100% ok, this seems to be leaning towards a “Starter” or “Starter Solenoid” issue? Yet, why would the car shut off while she was driving???

  20. Guest says:

    Exactly my thoughts. The starter may be intermittent, but it won’t make the car to shut off by itself.

    If it would only be a starting problem, I would say it is the starter itself, but more commonly, the ignition switch.

    But, since the car is shutting off by itself, the problem seems more to be in the security system. Those systems normally send an ignition off signal, along with a starter cut off signal when triggered. If it is so, triggering the security system could be caused by a malfunction in the system itself or intermittent wiring. Reminds me the systems that turns the car off after a few minutes if it is hijacked.

  21. wanito says:

    i have a situation on a vehicle has lost keys and no spare key on the immobilizer type too
    i order the new keys and there 2 keys has arrive and can you please to advise me for
    how to i programmed it without the original key because i dont have left the original one
    also i don’t have programmer tools
    thanks i appreciate your reply on its
    details of vehicle below:
    model :BDG-XZU508V-RETMA
    engine: NO4C-TH 4009ml
    frame : xzu508-0004460

    thanks again
    with many thanks

  22. zilog357 says:

    Hello Wanito. I haven’t work on those models, but all Toyota models I know, if all keys are lost, the only way of making a new key work is by taking the eeprom chip out (desoldering it) of the immobilizer unit, reprogramming it with the corresponding “virgin” file and putting it back (soldering) in the circuit. I am sorry, but without any master key, all the easy methods (by using accelerator and brake pedals) will not work.

  23. Cedar says:

    Hello, I just bought a 2003 Toyota corolla manual transmission. I’ve had one day. the car requires to push what is actually the mirror button ( valet button? ) and hold clutch to start. the mirror button has now been pushed right in and I’m also seeing another wire with a switch on end of it but is just hanging. I can’t start car now. I don’t have mast keys it seem there are only valet keys? They don’t have plastic on them at all just all metal keys. How can I fix myself ?

  24. marsha says:

    Hello. I have a 2008 carolla axio, push start. It is not starting. The engine cranks then shut off. It was scanned it states immobilizer error but the experts can’t seem to fix it…it about a week now..what do u suggest?

  25. David says:

    My Toyota Yaris ’08 has a perceived immobiliser problem as it doesn’t recognise the only key’s transponder code and refuses to start fully. However after disconnecting the battery for a while it then recognises everything as it should and runs errorlessly until the next time?
    Does anyone have any sage advice please.

  26. Archi says:

    Hi I have a 07 Camry v6 I had a check engine light on for the camshaft position sensor. Car was running fine one day I got home turn the car off the next morning I tried to turn it on and it just turned over. Not sure what is going on I tried scanning the car with obd2 scanner and it’s having a problem connecting to the car. I’m thinking it’s the ecm or Immobilizer. Please help thanks!!!

  27. Rob says:

    Hi’ I have Toyota corolla 2005 . when I insert the key. security light doesn’t go off , vehicle does crank but it won’t start . I have change battery inside the key but still ,even if I press close Or open batten on the key it doesn’t respond . please advice can a build in immobilizer be removed .please help . thank you

  28. zilog357 says:

    Hello Rob. Looks like the immobilizer system of your Corolla needs to be serviced. It can not be removed, as it is part of the ECU internal programming itself and does not rely on any external part that can be removed to deactivate it.

    Most of the times (99% in my cases), it only needs the immobilizer to be reprogrammed (some call it “reflashing”). If reprogramming does not solve the problem, then you will need to look at the other immobilizer system’s components.

    In Toyota Corolla’s sold in USA, there are two variants, one with an external transponder ECU (Immobox) and other without that box. So the Corolla immobilizer system components in order of which one fails the most to the less are:

    The immobox (not all models)
    The ECU (Engime Computer)
    Transponder key
    Ignition switch antenna and amplifier (all in one box)

    Programming needs a specialized tools for your Toyota model or doing it directly with an eeprom programmer and the file needed to be written in the chip. If using an eeprom programmer, you will need to reprogram the chip in the immobox if present (IC900). Otherwise, the chip in the engine ECU is the one to reprogram. For programming or removing the chip you may see the following articles:

    I am not sure of what ECU number you have, but here, many ECUs can be re-synchronized with the immobilizer system by jumping two wires in the OBD diagnostic port. The information on this is in this same article.

    I hope this helps.

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