Toyota Corolla Immobilizer
This article was made as a companion for the Toyota Corolla Immobilizer Reset Service we offer for the 2005-2007 Toyota Corolla, but it could also be helpful for you if you own one of those models and recently replaced the ECM with a used or recycled one and your car is not starting.
When you replace the ECM of these Corolla models and the replacement ECM is not brand new or at least was not previously reprogrammed, the engine won’t start because the used part has in memory the old key codes of the keys from the donor car. Those codes will not match the codes of your keys and will create a no-start situation.
Identifying the situation
Please note that with “no-start“, I mean that it cranks ok (the starter motor runs), but the engine does not start. If instead, the starter motor does not run either, then the problem is not the immobilizer and could possibly be an aftermarket alarm system that comes with many of these Corollas. The rule is; an immobilizer problem will cut injection and/or ignition but will let the starter motor crank. A problem with the anti-theft security system (alarm) will cut the starter too. If the problem seems to be the alarm, We are providing some instructions for that situation too under the heading “The Alarm system” further below on this article.
Your car may include one or both of the following:
- Immobilizer system (factory installed): Disables injection and/or ignition by internal means (ECM)
- Alarm / Anti-theft system (aftermarket installed): Disables starter. May disable injection and/or ignition by external means (Wiring).
What to do (immobilizer)
Ok, the ECM was replaced and the car won’t start? We have two possible solutions here. You may either; (1) perform an immobilizer synchronization (sync from now on) between the replacement ECM and the immobilizer system of your Corolla or, (2) if that does not solve the problem, you may use our corolla immobiliser reprogram service to reprogram the immobilizer of the replacement ECM.
The first solution above (sync process) may fail to do the trick if; (1) the memory chip in the ECM where the key codes are stored is full (it has a limit on how many key codes can be registered), (2) the memory chip is defective or damaged or (3) the ECM is damaged.
The good news is that the first solution (sync process) is free and most of the time it solves the problem and even when it sounds kinda complicated, it is a very easy to do procedure, and you can do it yourself with just a bare paper clip. It is explained in detail below.
Interested in the full wiring diagram of the ECU connections of the 2005-2007 Toyota Corolla?
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The Sync Process (Free, Do it yourself)
To sync your replacement ECM with your car’s immobilizer system you will need to jump two connections in the OBD diagnostic port terminal for 30 minutes with the car key in the “ON” position. That is, all the way forward, right before starting the engine.
Because the ignition and all systems will be turned on, but the engine will not be running, you need to make sure that your car’s battery is fully charged or you must connect a charger to the battery while doing the sync process to ensure that voltage will not drop. If the voltage drops considerably (below 12 volts), the process must be restarted all over again and wait another 30 minutes. Also, it is important that if you are going to connect a charger, it must not be in “trickle” mode and it must be of good quality in order to avoid electronic noise from the charger that can negatively affect the sync process. If you do not have such a charger, then it is recommended that you fully charge your car’s battery first with any charger and then do the sync process, but do not use the charger WHILE doing the process.
Steps
A) First, locate the diagnostic port. It is under the dash in the driver’s side under the steering wheel, near the hood release lever. It is a dual-line 16-pin connector (8+8). See the illustrations below as reference.
B) Now, with the engine off and the keys in “off” position, jump connectors #4 and #13 of the diagnostic port by using a bare paper clip. Below are example illustrations.
C) Next, with the paper clip in place, turn the key all the way forward to “on” position (ignition on) right before engaging the starter and leave it there for 30 minutes.
Different lights in the dash panel will start flashing. This is an indication of the process going as expected. If lights don’t flash, then something is not working as expected and you should start over. This not happening as expected can be caused by a poor electrical connection in the jumper you made or if jumping the incorrect connections of the OBD-II diagnostic port terminal. Make sure you are using connection #4 and #13 as instructed previously before proceeding. Below is an animated GIF of what it should look like when it is working correctly, so you can have an idea.
D) After 30 minutes, turn the key to “off” position and remove the paper clip from the diagnostic port. After removing the paper clip, you may attempt starting the engine. It should start at this point if the ECM and everything else is good. If it does not start, you may send us your unit so we can program it.
The Alarm system
If the problem is that the starter motor is not running (not cranking), but all electrical systems seem to be right and the battery is charged, then you should try to reset any aftermarket alarm or anti-theft system if any (not to be confused with the immobilizer system). The ECM, good or not, will not prevent the starter from engaging. The immobilizer system will disable injection and/or ignition, but not the starter. So if the engine is not cranking when you try to start the car, it is not necessarily the ECM or the immobilizer system in most cases.
What happens in most cases is that any aftermarket alarm or anti-theft system will need to be reset if the car battery is disconnected longer than a specific time, usually in minutes. In those cases, it is this aftermarket security system that is disabling the starter.
Some Corolla models come with a security light that serves as an indicator and it is a button at the same time. Below is an example illustration:
In most cases, to reset the alarm you may try arming and disarming it with the remote control provided for it (key fob). If that does not work, then try the following:
1 – Insert the key and turn it to on position, but do not start the engine.
2 – Push the red security button (picture above) twice.
3 – Now start the engine.
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?
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.
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!
I am glad you brought your car back to life. It was a pleasure helping you.
Richard
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
Regard
Jan
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.
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
http://www.drdetailshop.com/Transponderreference.htm#TypeE
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.
Firstly:
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.
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.
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..
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,
Richard
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
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.
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
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
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.
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.
Regards,
Richard
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?
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,
Richard
http://www.ThechnicalDomain.Net
2005 Toyota Corolla Starting Diagram:
https://qcwo.com/2005_corolla_starting.pdf
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???
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.
hello
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:
toyota
dyana
model :BDG-XZU508V-RETMA
engine: NO4C-TH 4009ml
frame : xzu508-0004460
thanks again
with many thanks
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.
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 ?
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?
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.
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!!!
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
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:
https://qcwo.com/technicaldomain/simple-immobilizer-smd-eeprom-removal-and-replacement/
https://qcwo.com/technicaldomain/reading-writing-immobilizer-eeprom-in-circuit/
https://qcwo.com/technicaldomain/working-with-immobilizer-software-for-virginizing-files/
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.
I want to know how to program Toyota smart key
After resetting the Immobilizer, car will start accepting the new key. It could be original master key or a brand new key. From other comments, you said
“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.”
But why is method doesn’t work for new key?
Hello Alan. If the key is a compatible key, it should work. I am no longer working with keys, but I have successfully done that with keys for the Rav4 and Corolla models. Have you considered maybe having problems with another area of the immobilizer system? What model is it? Are you using the correct virgin file? Do you have keys that are already working in that model?
Hi Zilog357,
Maybe I didn’t make my self clear. You said the program the “virgin” file is the only way to make the NEW key work, which means there is no other way to do it.
I want to try your method in your article (jump connectors #4 and #13) to reset the immobilizer, and register my new key, because I think the ECU doesn’t care if the key is new or old, as long as the key can emit the RFID signal. Please correct me if I’m wrong.
To answer your question, I have a 2005 corolla and my immobilizer system was working fine before I lost my keys. I didn’t try to virgin my ECU. I lost all my original keys, and have purchased a new un-programmed key from the dealership. I saw the post talking about how to virgin the ECU but it seems too much work to me. https://www.instructables.com/id/DIY-Immobilizer-Hacking-for-Lost-Keys-or-Swapped-E/
Alan,
“I want to try your method in your article (jump connectors #4 and #13) to reset the immobilizer, and register my new key”
Unfortunately, that will not work. That process is to synchronize the engine ECU with the immobilizer ECU. It does not cover the key.
” because I think the ECU doesn’t care if the key is new or old, as long as the key can emit the RFID signal”
The ECU doesn’t care as long as:
(1) The key is compatible – There are different algorithms among different models
(2) The key code is already registered in memory – The RFID transmitted by the key will contain a code. If the code is not registered in the eeprom chip, the system will reject it and the engine won’t start.
If your key is brand new and it is compatible with your Corolla, then it will fall in #2 above. That is why the eeprom chip will need to be virginized. Virginizing the eeprom will erase all the existing codes, which is good because it has room for about 8 keys only and will put the ECU in “auto-register” mode, which is a mode where it accepts and registers the first three keys used to start the engine after the eeprom is virginized. Then it will only start with the registered keys.
“I have a 2005 corolla and my immobilizer system was working fine before I lost my keys”
Then in your case, a new key a virginized eeprom is the way to go.
“I saw the post talking about how to virgin the ECU but it seems too much work to me. https://www.instructables.com/id/DIY-Immobilizer-Hacking-for-Lost-Keys-or-Swapped-E/“
And I don’t blame you. That is way too much work for a simpler task. For that, I just put a micro-pincer wire in each lead of the chip and reprogram it without desoldering and soldering back. The micro-pincers need no soldering. To program it, I use an eeprom programmer. The extra stuff in the video is to do it without having the needed tools I guess.
So you will either need to reprogram the eeprom with a virgin file or replace the eeprom with an already virginized eeprom. If you don’t have the programming equipment, but can replace the eeprom chip (desoldering the old out and soldering the new in) then the second option is best for you and I can provide an already virginized chip.
If you don’t have the skills or the tools and/or the programming equipment and prefer to send your ECM to be virginized, contact me privately by using the contact form in this website. I can offer a free option.
Kind regards,
Richard
Hi i have swaped the 7m in my 7mx83 for a 1jz gte vvti that has an immobiliser.
I need a wiring scymatic for an 01 Toyota crown athlete, and a solotion for the immobiliser..
Hope u can help pleaser,and thank you,
Hi,
does this ecu paper clip reset work on both Petrol and Diesel models, or just Petrol.
Many Thanks
Mike
Hello Mike.
Unfortunately, we work only we petrol engine cars. It works perfectly on petrol Toyota models, but I have never tried that in diesel engines.
My guess is that it should work the same in diesel models, as what it does is putting a “vendor reserved option” pin (pin 13) to ground (pin 4) to activate a function. So pin #13 is reserved by the manufacturer, in this case, Toyota, for installing custom functionalities. Diesel engine models are no exception.
You know, the key to knowing if it is working correctly in petrol engine models is by checking the dash when the clip is connected and the ignition turned on. If the dash lights flash randomly, then it is on its way. So if you do this to a diesel Toyota model and see the flashing lights right after the jumper is placed and the ignition switch is turned on, then it is working and you can leave it like that for 30 minutes to complete the process. If you were just testing whether it works or not, you don’t need to wait the 30 minutes and can turn the ignition off and remove the jumper anytime and nothing would be broken.
I have a 2013 RAV4 just got new immo . Does it auto accept new keys after. 4-13 jumper is removed!
If it is brand new, then it should accept the new keys even without doing the jumper thing. But if it is not new or it is new but not accepting the keys, then yes, the jumper thing should do the trick.
Remember to make sure that the battery is fully charged. Also, if the dash panel lights are not flashing while waiting for the 30 minutes, then something is not working, like for example, the jumper not making good contact.
I hope this helps.
Ok before I did jumper immo light was off. After it is flashing . Is that good or bad? Now what do I do? Is there any combination I need to do?
Zilog357 I did the jumper twice on new immo how do I add keys to a 2013 RAV4? Think I need to take to a locksmith?
Besides the flashing light, did it start with any of the keys? Did you try all the keys you have?
The jumper process is for adapting the immobilizer system of the vehicle to a used ECM. If a brand new immobilizer (immobox) was installed, it is not supposed to need the jumper process. I suggested doing so because of what you described that you installed a new immobilizer and it was not starting. This would reset everything and rule out the possibility of any code in the immobilizer.
After the immobilizer is either reprogrammed or replaced by a brand new one, it should be in “auto-registration” mode, where it accepts and register automatically the first three keys used to start the engine after installing the immobilizer. So if the immobilizer was new, you should be able to start the engine with the existing keys.
If all that fails, then there could be a problem with the wiring or the ECM.
I am assuming things here. It might help to know what happened to the car before all this. I mean, why the immobilizer was replaced in first place. Did it stop starting out of the blue or were the keys lost?
immo had water damage on these components tms3705bg4 , the oscillator next to it and on 11910 also c31 was broken off and missing a pad. the dealership told us to do 4-13 to handshake the ecu to the ecm. so you think the damage may have went to the ecm as well?
i ordered a 2.0.4 mini vci cable. i will let you know what the results are later today. this is the first place on the internet that gave any response . thanks
The ECM may have problems too, but in my experience, when the immobox is damaged, most of the times it is just that. Then jumping pins 4 and 13 will synchronize the data in the ECM with the immobox (Transponder ECU).
In some models, the security light will flash steadily when it is expecting keys to be registered and won’t go off immediately in most cases unless at least three keys are registered. That is, starting the engine with each one of the keys. If the three keys are not registered, the lamp will go off eventually when the auto-registration cycle closes but may take one or two days.
Also, watch the flash sequence just in case it is flashing a code. Sometimes it flashes a 2-digit code with pauses between the digits.
The immobilizer system in those models is composed of (1) the engine ECM, (2) the immobilizer ECU, (3) the ring antenna with the amplifier in the ignition lock, (4) the keys and wiring. So if the problem persists, I would first check the wiring. I am not sure if you have the wiring diagram of that model, but if not, I am including it here.
2013 Toyota Rav4 Engine wiring diagram
2013 Toyota Rav4 Immobilizer wiring diagram
http://www.ti.com/lit/ds/symlink/tms3705.pdf data sheet to the tms3705bg4 i realized just now that that chip could have broken the antenna or amplifier when it shorted out.i will find out later today if that is the case.
Check the diagrams I sent you in the previous message to see the connection and open both the immobox (or use the damaged one for reference) and the antenna amplifier to see if there is a direct connection, as I am not sure if the data is coupled by resistors. If it is, then there is little possibility that the short had broken the amplifier. If data is fed directly, then you may be right.
Since there was water damage, consider the possibility of water damage in any other area or wiring that could be affecting the immobilizer.
Just throwing darts in the dark because of course, I am in front of the vehicle and the problem is not a common one.
i have a mini vci 2.0.4 . does one of these read the k and L lines? i can’t read most of the systems in the rav 4
i hate to ask . do you have the schematic for the obd2 connector?
Yes. It is called the Datalink and you will find it at the left in page one of the diagram in the link below.
2013 Toyota Rav4 Datalink connector Diagram
Cheers
Hello, I hope with your knowledge, you will be able to steer me in the right direction.
I have a 05 corolla xrs 6sd that was given to me without any keys. Before it was given to me the person before me had removed the original steering wheel column and replaced with a new one. Problem is, someone stole the key that went to the new ignition.
So my question is, before I spend money on doing what I hope will work. What are my options and will any of the answers you’ve given work for my scenario.
If I need to replace my locking key switch must I also reset the new keys to match the code of my anti-theft system 2005 Toyota corolla immobilizer?
To do the rest on my own what exactly must I do or does this require a professional to do the reset?
Hello Anthony.
If replacing only the switch, you won’t need to do anything else. If replacing the key lock, then it means needing a new key cut to it.
If replacing the key lock, the new key should be cut and registered in the ECM of your car so it can start the engine.
The ECM must be programmed for auto-registration mode so you can register any new key when the key lock is replaced.
We can do that. The service is in the link below:
https://qcwo.com/technicaldomain/product/2005-2007-toyota-corolla-immobilizer-reprogramming-service/
Other than the service above, the only workaround I know will need a new transponder key (the new key for the new switch) and a blank key cut to the new key lock (bare metal, no chip, no plastic handle).
If doing that workaround, once the new keys are cut (the new key and the bare metal key) and the new switch is installed, you can try the following process to try to register your new key:
1. Tape your new bare metal key and old key back to back together, one pointing away from the other.
2. To do an initial test, try to start the car with the bare metal key, while the old key taped to it points away from the ignition. If it starts, then it passed the test and you can proceed to register the key with the process below.
3. Keep handy and away from the ignition all the 3 keys (the old key, the new key, and the bare metal key).
4. Insert again the new bare metal key with the taped old key without turning it, just leave it inserted in the ignition.
5. Now, within 15 seconds, depress and release the accelerator pedal 5 times.
6. Now within 20 seconds after step 5 above, depress and release the brake pedal 6 times.
7. Within 10 seconds, remove the old/bare key combination and insert the new key to be registered in the ignition, also without turning it and depress and release the accelerator pedal once.
8. The security indicator should be flashing. Wait for about 1 to 2 minutes or until the security indicator turns off. After this, remove the key and depress and release the brake pedal once.
At this time, the new key should now be registered and you should start the engine with the new key.
Repeat all these steps for every key you want to register.
I hope you succeed.
Kind regards,
Rick
I have a ae112r hatch I’ve lost my key
And brought 1 from Toyota is there anyway I can program it
Thank you
Hi. 2007 solara. I removed my dash to fix the ac and cracked the immobilizer….car cranks won’t start. I have a donor car so I removed the immobilizer from it and used it. Went thru the reset procedure (pin4/13) and still wont start. I moved the ignition switch from the donor car and used its key and won’t start…after resetting again. Any help appreciated.
Hello Toby.
Assuming that the immobilizer box (transponder ECU or “immobox”) is good, is it the same part number (89780-xxxxx”)?
If yes, then the sync process is for accomodating a used ECM (Engine Computer) from a donor car, not the immobox.
For the immobox, there are processes done through the diagnostic port using Toyota’s TechStream software. Alternatively, a more “home-made” process, is to simply transfer the EEPROM chip (8-lead SOIC chip) from the cracked immobox to the replacement immobox. That is, desolder the chip from both boxes, and put the chip of the old box (it has the codes of your keys) in the replacement box.
Again, this is assuming that the replacement box from the donor car is in good working conditions, oh, and also assuming that the chip in the broken immobox is not broken.
I hope this helps.
hello. is it possible to do this here in your listing. for a 1997 toyota starlet 1.3 petrol.
ecu type 89661-10240, and immo box type 89780-10010.
all keys lost to car. the main ecu is ok. but the immo box has got a corrupted i.c 8 leg
24c04 chip. and was not poss to take a dump/ reading out of it. poss due to heat on removing to eeprom a make key.
can a second hand immo box be fitted. and do this obd match with pins 4 and 13 with a paper clip.
do not mind if i have to buy a ecu and immo matched of another vehicle.
Hello Richard.
The 89780-10010 immobox can be virginized so the car accepts new keys. The virgin file for the EEPROM of the immobox can be downloaded in the link below:
1997 STARLET VIRGIN FILE
Unzip password: TechnicalDomain.net
(the password is case-sensitive)
Just download the file and write it to the 24C04 EEPROM.
Cheers!
I have a Toyota Corolla 2005 that the anti theft alarm is not alerting again after lock, but when I press the panic botting from the remote it make the alarm
Hi Folks,
Can I use this procedure to add a second key, or does the procedure delete any existing keys?
Thanks for the help,
Hello Chris
The procedure will not delete the already stored keys. That is why the ECM will need to be reprogrammed if the key memory space is full, which depending on the model, could be anywhere from 4 to 8 keys.
So if you have a replacement ECM and it is donated from another vehicle, this process will work and your keys will work too. Again, unless the memory is full.
On the other hand, if you have a working master key and all you want is to add a new key, then you may use your existing working key to register another one with a simple process, assuming that your new key is already mechanically cut for your ignition.
The following process is for registering a new key. Please read it through beforehand so you get familiarized with the timing. For all steps, there is a time limit of seconds that cannot be exceeded or the process will not work.
Process:
1. Insert the existing working master key and do not turn it. Just leave it inserted in the ignition.
2. Within 15 seconds after Step 1 above, depress and release the accelerator pedal 5 times.
3. Now within 20 seconds, depress and release the brake pedal 6 times.
4. Within 10 seconds, remove the Master Key and insert the key to be registered in the ignition, also without turning it and depress and release the accelerator pedal once.
5. The security indicator should be flashing. Wait for about 1 to 2 minutes or until the security indicator turns off. After it turns off, remove the key and depress and release the brake pedal once.
The new key should now be registered now and working.
Repeat all the steps above for every key to be registered (until the memory is full).
If a key fails to register, do not immediately assume that the memory is full. Try again and make sure that you are following the process exactly as described. Also, make sure that you have a compatible key. There are several key types used in Toyota models with different security and communication protocols, so make sure you have the right key for your model and year.
Kind regards,
Richard
Will this procedure (short pins4 and pin14) also do the zero point calibration (yaw sensor)?
Background of my questions is a Toyota Corolla Verso 2007. I tried to do the zero point calibration with pin4 and pin12 and that did not work (no response on the display like you showed nicely in the gif)
Thanks
Wim
Sorry typo in first sentense: sound be pin4 and pin13
Hello Wim. Unfortunately not. The process (shorting pin4 and 13 of the OBD port) only works with the immobilizer system.
Any other calibration of the system must be done with a scanner capable of doing it. For instance, the Toyota’s TechStream system.
Kind regards.
thanks
Toyota corrola 2006 immobilizer got damaged by water ,,so I have replaced with the immo of the same number
Pls how can i reprogram the new E C U immobilizer with the car Immobizer system
Hello Toheeb.
Have you tried the sync process in the link below, shown when you scroll down the page until the title “The Sync Process (Free, Do it yourself)”?
https://qcwo.com/technicaldomain/toyota-corolla-immobilizer/
It is used for synchronizing the immobilizer system between the ECM (Engine Control Module – “89661-02xxx”) and the Immobox (Transponder ECU – “89780-xxxxx”), that is needed to be done when replacing either unit with a used unit.
Kind regards,
Richard
Thanks for that sir
Please sir ,,can I have your WhatsApp number to get quick reply from you?
hola muchas gracias por esta ayuda y el archivo de inicio,. mi pregunta es si me podrian enviar un achivo de immo off para colocar una computadora de rav que originalmente usaba immovilizador y colocarla en una rav que no utiliza immovilizador un cordial saludo
Dear Admin
I have a Toyota Corolla, that swings but does not fire up, read through the comments and wonder could I not have a problem with my alarm/immobilzer system. I had my steering rack recon as it was leaking fluid under the brake pedal and also changed engine mountings, after this I started having trouble.
Does the immobilizer/antenna/capacitator of a 1999 model 160 GLE influence start up
Hi Richard,
I have a 2006 Corolla that used to have a key fob with no lock or unlock functionally, just a button that I’m not sure what it did. I’ve since lost this key fob, and now the car won’t start unless I turn the key 7 times. I need to do this every time to start the car.
Will one of the fixes you’ve posted here work for this issue, or is this something that the dealer needs to fix somehow?
Thank you,
Kenji
Hello Kenji. Unfortunately, our solutions are focused in the immobilizer system only. The immobilizer system is directly built within the ECM. By the symptoms you are describing suggests that the issue you are having maybe is related with an alternative security system. The thing with the key 7 times, is for programming keyless entry key fobs when bought new.
Please let me explain:
The immobilizer is a security/anti-theft system, installed directly inside the ECM hardware in the ECM factory. It disallows the car to start if you don’t have the proper key with the proper programming in the chip inside that key. No key fob, just a small chip inside the plastic handle of the key (it is not noticeable).
Ex: Chip inside the key
The characteristics of a problem with the immobilizer system is that it allows the starter to spin (crank the engine) when attempted, but the engine won’t start. No sound is produced from the horn.
An anti-theft security system, sometimes called the “alarm system”, is the system that does not allow your car to start when the doors are opened while the system is armed, or if a window is broken if the vibration sensor(s) is/are installed, and that kind of stuff. It also sounds the horn or a bullhorn to scare off thiefs.
The characteristics of a problem with this system is that it will NOT even allow the starter to crank the engine.
—
As you can seem, both are anti-theft security systems but are physically separated, do not conflict with each other, and each one covers different security areas.
—
Check and try this:
If the car has a red “alarm” or “security” button, usually located in the dash to the left of the steering wheel, have you tried the following?
1. Put the key in the ignition and turn it to “ON” (right before the “start” position).
2. Push the red button twice
3. Try to start the engine
I hope this helps.
Kind regards.
Hi. I have 2004 corolla 1.4i it starts and after few minutes stalls.
I have a 2001 Corolla ascent. I dropped the key, the remote broke & the button to unlock the doors and the immobilizer won’t work. The actual green chip is damaged. For some reason locksmiths near me don’t think it’s an original key fob and can’t be replaced. The car turns on but won’t start until you press the button again. Then the engine light goes off & the car can be started. I’ve included photo of remote. I thought it would be as simple as reprogramming a new one? Thank you.
I have a corolla 2003 3zz FE, I lost my keys I did want to cut a new key so I got an ignition barrel and keys from a donor car but my car won’t start it will just crank and the security light just blinks even when I was using the old keys and ignition barrel what can I do
Hello Mathews. Check if the car also has a transponder ECU, also known as the “immobox”. The box is usually installed behind the dash, near the fuse box of that area and it is held by only one screw. If your car has it (most Toyota models do), that part must be replaced by the old one too because it is precisely there where the key codes are stored. The part number always begins with “89780”.
Below is an example of one of those (click image to enlarge).
I have a 2006 corolla, was working fine until I tried to find a power draw (think battery was just bad). I pulled the wrong fuse which was for the ecu I think, left it overnight. Now it only turns over and not start. Did I trip my immobiliser? I have my master and a replacement I had made that worked before. Neither work now. What can I try?
Hello Austin.
Based on what you described, I think that the immobilizer got re-written somehow with wrong codes. The only way to surely fix it is by reprogramming the immobilizer chip in the ECM circuit.
Other than that, you may try the 30-minute simple immobilizer sync process, described in this article. If that does not work, then the chip programming is the way to go.
If needed, we offer the programming service in the link below:
https://qcwo.com/technicaldomain/product/2005-2007-toyota-corolla-immobilizer-reprogramming-service/
Kind regards,
Richard
hi there
I have a toyota corolla 2004 model, I changed the ecu with a second hand ecu, coded keys and the immo light goes of when I insert the key but when I start the vehicle it starts up and then dies, have no injection pulse then! What could be the problem?
thank you
Hello Jacques. This is rare because that is exactly the behavior of an immobilizer problem (code mismatch, etc.). I say it is rare because the security light is properly turning off like if it is accepting the key as a match.
Have you tried doing the 30-minute sync process described in this article? I know that you coded the keys but sometimes this helps.
Other than that, I cannot think of anything else other than the replacement ECM being damaged. What was the original problem with the original ECM?
Hi, I have a Toyota Corolla 1.6 E120 2003. The car just all of a sudden do not want to start, cranking but no start. As soon as I put the key in and turn it towards start, the Immo light goes on. I have tried the jumper on pin 4 and 13 for 30 min but that did not work. I suspect the Coil or Key ring around the ignition to have fialed. Is that possible or is iot possible that the Immo unit also failed? I ordered another coil/ring because as I understand that is just a reader and has no key information. Is there a a way to totally bypass the Immo even if I have to run wires from/to the ECU pins that needs power to get the car started. Thanks
Hello Chris. Unfortunately, the only way to do that is by (1) reprogramming the ECM immobilizer system and (2) disconnecting the key amplifier (antenna coil circuit) if no transponder ECU is present (immobox). If the immobox is present, then disconnecting it instead, after reprogramming.
The part #2 above is the easy one. The conflicting part is #1, which involves removing (desoldering) the immobilizer EEPROM chip, reprogramming it with the right code, and then soldering it back in the circuit.
About the “right code” needed, it is on a case by case basis. Since I have not seen that model sold locally here in the USA, I had never worked with the ECM to see what code is needed for the Corolla E120 ECM.
When you did the 30-minute sync process, if the lights in the dash did not blink as described, then either it was not done right (loose connections), or such system was not used in the model in question.
Finally, since you mentioned the antenna amplifier, there are some Toyota immobilizer systems with 3 components and there are some others with 4 components.
Some have (3):
-Transponder Key
-Antenna (key amplifier)
-Engine ECM
Others (4):
-Transponder Key
-Antenna (key amplifier)
-Engine ECM
-Transponder ECU (immobox)
If your model has an immobox, the problem could be there. The immobox is a small box connected with only one plug and held with only one screw. In the USA models, it is found near the interior fuse box behind the dash. That box (if present), contains the stored key codes to be matched when you insert your key in the ignition (look about 6 replies above this one for a sample picture of the immobox).
I am sorry I could not help better.
Hi Richard,
Thanks very much for the response. I did however change the coil ring around the key that reads the RFID but that did not make a diffirence which means it must be something else. BUT, 2 days later I wanted to remove the battery for charging and I thought just give it a try and it starts. This is not good though because now I do not know what is causing this. However, after I switched it of for 1 hour and tried again, the same symptoms appears which points to something else.
Do you think it is the ECU or the IMMO unit? I suppose I can not just replace the ECU as they RFID info is in there too or is it just stored in the IMMO unit? This is sooooo frustrating and I hope you have some direction on where I can search…
Thanks very much.
Chris
The RFID is only for communicating and is part of the core functions. At a higher level, that is, once the RFID system handshakes and communicates, there comes the part where the key codes are read from a key when it is inserted in the ignition and then compared with the key codes in memory of the immobox if present, otherwise in the memory of the ECM.
Then, the start or no-start condition is delivered from the immobox to the ECM, again, if there is an immobox, otherwise, the start or no-start condition is generated in the ECM itself.
So what I mean is, replacing any part (ECM, Immobox, etc.) deals with the codes of the keys, not the RFID. Since the parts are for the same car type, RFID will be correct for all. The issue are the encrypted codes from the keys when compared with the codes in memory.
Those codes in memory were registered there when the ECM was first programmed.
What seems off here is that the car started suddenly and now the problem is there again. An intermittent problem like that is mostly caused by faulty or intermittent wiring or intermittent connections. The immobilizer system is so tight that if the problem was with the immobilizer, the car wouldn’t have started again until the immobilizer is fixed or reprogrammed. The fact that it started again out of the blue means that the issue most likely is something else.
Another thought is, I have seen similar problems here but is has to do with the alarm system in the car (third party security system). Normally, I wouldn’t think of the alarm system (if any) because usually, the alarm system locks the starter too, disallowing the engine from cranking. While the immobilizer, allows it to crank but no start. So around here, “cranks but no start” = immobilizer, and “Not even cranks” = alarm. But lately I have seen some alarm systems that allow the engine to crank too and only cut the main relay (no ignition, no injection).
My first move would be a visual inspection of all connections.
My second move would be to start by checking ground problems, where you put the negative of the voltmeter to the negative of the battery (directly, using a long jumper wire since you will likely be measuring inside the car), then putting the key to “ON” position and using the positive of the voltmeter to measure voltages at the wiring of the ECM and the immobox (if any). If the voltage is considerably lower than the voltage measured from the positive pole of the battery, then you have a ground problem. It is IMPORTANT that you directly use the negative terminal of the battery as reference for the negative of the voltmeter for ALL measurements. Otherwise you will see no possible problems because you would be taking your ground from an already faulty connection. A good example of a car I worked with is, at the battery = 12.6V, and at the ECM = 10.5v. That would be a clear ground fault (only an example as values will be different in every case). In my case, it was the ring connector that goes from the battery to the chassis. It looked well, but it was corroded underneath when I removed it. I did not suspect of a ground because the starter was strong, but the ground form the starter is not taken equally as the ground for the electronics.
If the above tests good, then one very common possibility fewer to check.
Hi Richard,
After a couple of more efforts to get to the bottom of this, I got a ODBII scanner (surely not a good one but it works on my other 2005 Avensis) and the scanner could not communicate to the ECM. It fails to connect (communication failure) …I would like to think that points to a problem in the ECM.
Now my questions is if I get another ECM, should I be able to “reprogram” the key information to the new ECM though the method of bridging pins 4 and 13 for 30 mins as the key information should be in the IMMO.. I can get an ECM with same part number.
Thanks again man, appreciate the time you pit in to answer our questions…
Chris
Good morning.
My 2006 Toyota Corolla CE wont start. It has been parked for a long time and I would start it every now and then but one time I went to start it and it would briefly start and quickly shut off. It is the original ECM and immobilizer and I have 2 original master keys and all do the same thing. If I try the reset as mentioned above, will it do anything to my ECM or my immobilizer? Thanks for all your information so far.
Phil
Hello Phil.
No, it won’t hurt the immobilizer system or the keys. What it will do, is try to sinchronize the code in the transponer ECU memory (immobox) with the codes of the keys. In case that the problem was a corruption of the data for any reason, that should fix it.
the worst thing that can happen is that the car does not start if the problem is something else, like a secondary (non-factory) security system, like an alarm.
I have seen alarms that somehow have been silently triggered and will not allow to run the starter and there will be no crank, but I have also seen, like in your cae, some alarms that do allow cranking but cut injection.
If th alarm is the problem, you will just need to reset it. If the immobilizer is the problem, the sync process should solvge the issue. If not, the next thin would be to reprogram the ECM with the auto-registration code, which will allow the ECM to automatically re-register the key(s) you have by starting the car with all the keys present as soon as the reprogrammed ECM is installed.
There are different ways to reprogram the ECM:
The most expensive is using the official ways (a locksmith with licensed Toyota software (Techstream) and purchasing a token (only available to authorized locksmiths) to generate the needed code.
The less expensive is the one we do. We already have the needed code, so we take the immobizer chip out of the circuit, reprogram it, and put it back in the ECM and it will be ready to be reinstalled in the car.
Hopefully, the sync process will eork, or it will be something simple like resetting an alarm. If not, below is the link to the service we offer for that situation:
Immobilizer Reprogramming Service
Kind regards,
Richard
Hello,
My poor mother has a 2006 Toyota Corolla 1.8 she bought brand new. And I have done a lot of digging to try to find out this intermittent problem. I have read thru these comments and so before I describe the issue, Ill give some background.
2 original master keys and 1 valet key, all originals
The antenna ring has been replaced
The factory alarm, which was more of a keyless entry was taken out.
This is not a starter kill situation, it is the typical security light blinking, not on issue.
Here it goes:
On any given day I can use the master key and it will start fine. Thorough the course of a day, it can start all day long with the master key. Or the light may not go out. Sometimes I can put in the valet key and it will light up for a couple seconds then go off and it starts. Sometimes not. Sometimes both keys will not work. I can sit there for ten minutes at a Costco pump after filling up and it will not start. I usually just put the key in just enough to see if the light goes out, don’t have to foolishly try to crank it with the light still blinking.
It can go all day working fine.
Day two, master key will not start the car in the morning, but valet key will.
Day three, master key or valet key will not start the car. Come back 1/2 later the master or valet will start the car.
Day 4 Master key works all day. Try to move the car at night, and master or valet key will not work. I can try 30-40 times putting the key(s) in and most of the time after about 10 minutes one of them will work. Usually after I let it sit for 5 minutes it will work.
I personally have witnesses two episodes (and two only) where the car fires up for 3 seconds or so, and then it dies, and the light goes on.
This has been going on for about 2 years. I had to get a couple other things fixed on the car in my hometown, why my mom drives my car. So it has allowed me to see all the symptoms. My mom took it to the dealer in May. They did a diagnostic on the check engine light, catalytic converter, misfire etc. Those things got fixed, but not thru the dealer. I wasn’t there to deal with it, but I noticed on the service ticket it pulled a immobilizer code, B2779.
So to summarize, It will start about 70% of the time first try. 3 out of 10 starts it will not, no matter what key I use.
Any help would be appreciated.
Kind Regards
Joey
Hello Joey.
Thank you for your message.
DISCLAIMER:
Please remember that all these are just ideas of me thinking in the description you provided and the experience I have had with that car. Diagnosis, measurements, inspection, etc. have to be done to have a real idea of the issue. So the following is to be taken into account depending on what you find.
—
Just to be clear, since you mentioned that it is not a starter kill problem, I am assuming that every time it fails to start, it is cranking ok, just not starting.
If otherwise, it could be an intermittent failure with the ignition switch, or the starter itself, or the wiring between those. I know that you mentioned that the alarm was removed. Just make sure that there is not anything from it left that could be affecting this function. Most alarms impare the starter but I have seen some that only cut the injection and allow the starter.
With that out of the way, when the immobilizer system fails for any problem, it usually keeps that way, not starting. So the intermittent issue, if not what I stated in the paragraph above, it seems to be an intermittent connection issue. You know that for the immobilizer system, you have the ring antenna (you mentioned that it was replaced already), you also have the engine ECM, and you have the Transponder ECU (immobox). You also have all the wiring connecting all those modules.
If the ignition switch/starter is ruled out (it is cranking no problem when not starting), I would start by checking the wiring connections on each module and also a ground connection.
ABOUT WATER DAMAGE
You will notice that I am mentioning water damage several times in this message. It happens that sometimes water from the AC evaporator can damage electronic components in the interior of the car if the draining duct gets clogged.
GROUND
This is the one that should be checked first. A poor ground connection makes that insufficient voltage gets to the system and produces an ambiguous or intermittent behavior.
The first ground to check is the ring connection from the battery’s negative terminal to the chassis ground. This may look good but could be oxidized inside. It would be a good idea to disconnect it, clean it with a wire brush or sandpaper, and reinstall it. I remember one case (another Toyota model) that the customer was saying that it could not be the problem because it is cranking right and a bad ground connection would not allow the starter to run because of the high current demand for a starter. That is right, but when I disconnected that ring connection it turned out that the starter was not a good indication of a good ground connection because it was taking its ground from other connection. That bad ground connection was oxidized and the electronic systems were receiving like 9.5 volts out of the 12.6v available.
OTHER CONNECTIONS:
(DO ALL THIS WITH THE KEY OUT AND AWAY FROM THE IGNITION)
Immobox (Transponder ECU):
The immobox is a small box located near the interior fusebox, up, behind the dash panel, to the left of the steering wheel. You can reach it from under the dash. It has a single connector and it is secured by only one screw. Remove it and do a visual inspection and make sure that it has no indications of water damage. After that, disconnect it, and inspect the terminal and the connector. If all looks good, connect and disconnect the terminals a few times to remove any possible material impeding a good electrical connection and install it back.
ECM (Engine Computer):
Do the same with the ECM. The ECM has 4 connectors and it is installed under the glove compartment, secured by 4 Torx screws. Remove it and check for connections, check for possible water damage, and then connect/disconnect and install it back.
FUSES
I know this one is intuitive but I am not thinking of a blown fuse. I am thinking of intermittent connection on any fuse that could be exposed to water, either in the interior fusebox (under the dash, next to the steering wheel), and the engine bay fusebox. Just looking at the fuses will do nothing. A good idea would be to go taking out one by one, inspect it, and then reseat them into their place to remove any possible dielectric material. ALWAYS check the fuses with an ohmmeter. If the ohmmeter has a sound for continuity better yet. Fuses can look good and be intermittent or microscopically cracked anywhere.
MODULES
Immobox:
If all above fails to find the issue, the immobox is the first component to see if it needs replacement. On water damage, it will definitely need replacement. Otherwise, I can hardly find an immobox that is damaged by other than water damage.
ECM:
I have not seen that issue with the ECM but since it is in the group of the immobilizer system components, it is a (remote) possibility.
I hope this helps in any way
Richard
I have a 2010 Toyota Corolla. There are three dash lights that will not clear. The garage said it’s probably the ECU. So my question to you is, can the immobilizer be permanantly cleared off, deleted, rendered not working so you can use any key like when you get a used replacement ecu? Very hard to find anyone give a definite answer. most just talk about deactivating it to reset it. I think it’s a POS system and should be optional. I see deactivators on Alibaba, but with no information. So jumping with the paper clip deactivates it> Can it be permanantly jumped?
Hello Richard,
Regarding my moms 2006 Toyota Corolla with the intermittent start problem. Taken a few weeks to write back. I went under the dash like you had said, and found the immobilizer. Everything under there looked brand new, no dust or anything. I pushed on the wiring harness, and felt it move a bit into the immobilizer. So I pulled it out and in a few times, after looking at the female plug on the harness. Which looked brand new also. I am happy to say after that, it has worked every time for about three weeks now. Not one time has it not worked, since I messed with the wiring harness. I feel the problem is solved. I did replace the ground wire from the battery post to the metal also. Car seems to run better. I want to thank you so much for your information. Telling me where to locate the immobilizer was key. Also knowing that it could not be the immobilizer if it was working intermittently, important also. Now, It works flawless every time. I didn’t even look at the security light anymore after about a week driving it. I drove the car back to my mom’s and she about cried when she got her car back. All I can say is many thanks, especially from mom.
Hey Joey, I am glad that you could solve the problem. I hope the car stays working fine and gives no more issues.
Thank you for letting me know, I always appreciate the feedback.
For any other questions regarding the car, just drop a line. I’ll be more than glad to help the best way I can.
Hello Richard,
Good afternoon!
I’m from Brazil, locksmith and have a problem with 2003 Toyota Rav4.
I have ways to reset IMMO with Denso’s ECM but not to Fujitsu modules.
I have some questions:
Do you have any files resets to this module?
Could you tell me if this procedure can bring the immo communication back?
This car is a:
Toyota Rav4
Age: 2003
Transmission: automatic
Engine: 2.0 16v
I would like to thank you in advance for the support!
Hello Miguel.
The Fujitsu ECM is reset in the ECM itself, not in the immobox like many Denso ECMs. If the immo system is good, then yes, immo communications should be re-established with the correct file.
Please send me a message through the contact form of this website (Contact US) and a will email you the binary file. The EEPROM is a 25080.
Kind regards,
Richard
Miguel, I replied to your email. Check the spam folder if it is not in the inbox.
Regards,
Richard