Simple Immobilizer SMD EEPROM Removal and replacement
When you replace your 2001, 2002, or 2003 Toyota RAV4 ECM (engine computer or ECU) with a used or recycled unit, if your vehicle is equipped with an immobilizer system, which is an anti-theft security system, you must reprogram the ECM to work with your existing keys (immobilizer system).
In this article, we will cover the removal of the immobilizer EEPROM chip of the 2001-2003 Toyota Rav4 ECM circuit for either replacing or reprogramming it. This applies to either 4WD or 2WD models and to either Automatic or Manual transmission models.
Before programming the ECM, you should know that there is a simple process that car owners can do by themselves to synchronize the immobilizer data of the ECM to the Immobilizer system of the vehicle. We call it the Toyota synch process and what it does is exactly what its name suggests, synchronizing the immobilizer system data of the new ECM (replacement) with the immobilizer system data of the vehicle. This sync process is described in the article below and while it is for the Toyota Corolla, it is also exactly the same process for the Rav4 and it covers all Toyota models from 1999 all the way to the present.
If the sync process in the link above does not work, it could be that something was done wrong or went wrong in the process, or could be that the key memory is full (it has a limited capacity for storing key codes). The replacement ECM being defective is another possibility. At this point, you can go ahead and try programming the chip.
For reprogramming the chip, you will need an EEPROM programmer. You may do the programming either in-circuit or off the circuit by using a reset file. The reset file is the file that you will need to program (write) to the EEPROM. You may get that specific immobilizer reset file from us (FREE) in the form below:
Get the 2001-2003 Toyota Rav4 Immobilier file for FREE!
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NOTE: The chip file (program) available in the form above is for the 2001-2003 Rav4 models, equipped with the immobilizer system. The ECMs without the immobilizer system will NOT need this process. If in doubt, one way to know if your Rav4 has the immobilizer system or not is by checking the description in the article below:
How do I know if my 2001-2003 Toyota Rav4 has immobilizer (immo)?
You may check the article in the link below if you which to do the programming “in-circuit”. Please note that this option will greatly depend on the device programmer (EEPROM programmer) you are using. Some programmers will do the job just fine while the EEPROM is in-circuit, for example, the EETools ChipMax, but others will be more sensitive and won’t work in-circuit. In that case, you will need to do it off-circuit.
Reading and Writing Immobilizer EEPROMs in circuit
For doing it off-circuit you will need to remove the EEPROM chip from the circuit board (desolder it), reprogram it, and then solder it back to the circuit. We will be working here with the serial SPI EEPROM type “25080” (1024 bytes).
The EEPROM you will work with is near one of the two micro-controllers of the ECM. The reference in the circuit board for the EEPROM chip is “IC1003“. Below is a picture to be used as a reference.
In the picture above, you can see the location of the immobilizer EEPROM. Take note of the orientation of Pin#1, as the chip must be installed in the exact same orientation when you’re done with it.
Below, we will remove the EEPROM and clean the soldering pads from excess solder for when we are soldering back the reprogrammed EEPROM. Below is a simple method of doing it.
There are, of course, better methods like using a heat gun or using the famous “ChipQuick” tool, but we are showing the less expensive way and assuming that you do not have a heat gun or the “ChipQuick”, which are not very often in a hobbyist’s or beginner’s toolbox.
Cover with solder ALL 4 pins on each side of the EPROM. Make sure that the solder gets in good contact with all 4 pins on each side of the chip. Use a soldering iron which is not more than 35 watts.
Once the EEPROM is covered with solder on both sides, hold the EEPROM with tweezers, while heating both sides repeatedly until it is loose. After the chip is loose, just pull it up with the tweezers, away from the circuit board. Avoid getting molten solder in other areas of the circuit, especially in the nearby microcontroller. If it happens, remove it before you forget about it and power the ECM with it in the circuit. It can cause short circuits that can destroy the ECM beyond repair.
Once the EEPROM chip is out, clean it from excess soldering with a desoldering wick or desoldering braid. Chem-Wik is the market leader and the best one for that job. Remember always not to overheat the chip when soldering, desoldering, or cleaning it.
Now program the chip by writing the given file in it and before soldering the reprogrammed EEPROM back in place, clean from excess solder the circuit pads where the chip goes. Do it with the desoldering braid. That will allow accommodating in place the reprogrammed EEPROM chip more easily.
For soldering the reprogrammed EEPROM chip, put it in place and hold it with a sharp, pointed tool, while heating with the soldering iron one of the pins of the chip. That will temporarily lock in place the chip while the other pins are soldered. Make sure that you are putting Pin #1 in the right place.
That’s it! After soldering all the 8 pins of the EEPROM chip, make sure that; again, pin #1 is pointing in the right direction, make sure that there is no soldering debris on any part of the circuit and make sure that there are not accidental solder bridges, especially in the vicinity of the near microcontroller.
Now put your ECM back together and reinstall it in your RAV4. Then start the engine with all the keys you have so they get automatically registered.
for remover eeprom mazda 3 immobilizer in ecu you have picture?
Hi good day I lost my key from my VW Golf Mk1 1.4i 99mdl it uses a transponder key how do I read the 4 digit pin using Carprog I also have a T300 plus blue one but it also can’t read the pin code it only gives me the access code and the immo info The immo unit is Siemens and the chip inside is Motorola the only problem is I don’t have the diagram to soldier the pins with the A6 addapter
Location of immobiliser module on mazda axela 2006
halo please my problem is I have carprog and ad900 I want toturial and more explaination on how to programming eg golf,toyota,honda and the restplease even if its your forum I can visit and make sure I learn it very well thanks
If I buy a epprom for my 1999 Avalon do I just use the number on it to reference it or do I have to get one with programming in it ?
Hello Luke. You will need an eeprom with programming in it. Eeproms normally come empty. So you will either need an empty eeprom with the specific number (93C66, 94050, 24C56, etc.) and put the programming yourself via an eeprom programmer and the right file, or you will need an already programmed eeprom. Program in the eeprom must be the specific program for your vehicle.
Fantastic information posted! Really cool responses. Good job!
I have 01 Jeep Grand Cherokee… I bought with one key … I made screwdriver key .. and had know idea was chip in there and now immobilizer trouble car only runs 2 seconds… then dies …
How to program immo .
Hey man
I thought this might be a good one for you to see if possible. How to bypass H.I.S.S on Honda cbr929rr, eeprom been damaged and removed. Anyway to replace with blank chip and virginize? Or bypass hack ? I know it’s a good one hope this is a challenge!
Is the ee prom chip on a Volkswagen 2002 Jetta or golf once you plug that chip program and swapped over to a computer that was junkyard computer does that program the whole computer once you got that chip removed from the old one and put it in the new junkyard computer
Hello Larry. In many VW ECUs, the small EEPROM chip contains immobilizer data. The engine data is in a bigger chip. If you get a used computer, just take the EEPROM (8-leads chip) out of the old computer and use it to replace the chip in the new computer. That way, you will transfer the key codes to the new computer. The only thing that could be wrong is if the chip in the old computer is damaged, but not likely as it does not happen often. The chip could be a 93Cxx, a 950XX, a 250xx, or a 24Cxx chip.
Will my car start if I removed an epprom on ECU Toyota 2007?
Hello Presley. Depending on your model, some have two EEPROMs, one for the automatic transmission data and one for the immobilizer data. If you remove the EEPROM containing the immobilizer data then it will not start. If you are referring for example, to the 2007 Corolla, it will not start because that one has only one EEPROM.
Even Toyota cars without the immobilizer need the EEPROM. The EEPROM in the models WITH the immobilizer contains the data of the car keys. The EEPROM in the models WITHOUT the immobilizer contains the data for ignoring the immobilizer, but as you can see, there is always an EEPROM needed with the proper code programmed in it.
Just bought 2005 Corrolla. Security light blinks w/ key on ACC or Ignition. Ran for 1/2 second on initial try. No spark since. Pvs Owner had the ECM replaced & flashed by Pop-a-Lock. Has manual locks, tried several fixes incl A) sync process – jumping pins 4&13 of OBD2 port, B) Bypassing the system by turning the key to ignition for 15 min followed by 3 min in off position, C) Turning & holding the key in the door for 30 seconds. A code said cat problem so they pulled the exhaust pipe back a couple of inches where it has stayed. Any help would be appreciated.
If none of that worked, the only thing to do would be to program the chip inside the ECM. It must be unsoldered, reprogrammed, and soldered back.
We offer that service in the link below:
https://qcwo.com/technicaldomain/product/2005-2007-toyota-corolla-immobilizer-reprogramming-service/
After servicing the ECM, it will be in auto-registration mode, where it will automatically register the first key you use to start the engine, once the serviced ECM is re-installed. The VIN will be passed from the previous program as part of the service. Once the first key is registered, you will be able to register more keys with the gas and brake pedals simple procedure that will be explained if needed.
Kind regards,
Richard
Thanks Richard. I bought the Techstream and if it doesn’t work I’ll check into the key coil/transponder key amplifier & if that doesn’t resolve it I’ll definitely check out your solution. Thanks!
Sure, no problem.
You can register new keys with the help of TechStream as long as you have a functioning master key. In the cases that there is no key (I believe this is not your case), then it can do the same that I do, which is putting the immobilizer in auto-registration mode for registering new keys, but the difference is that I do it manually and TechStream does it without the need of disassembling the ECM of course.
If you are putting the immobilizer in auto-registration mode without having a working master key, then I believe that TechStream will generate a code so you enter a passcode against it to allow you to do it. If you do not have the calculator for getting the passcode generated against the initial code that TechStream gives you, there are services online that calculate the passcode for you for a small fee. The lowest I have seen is around $10-$20 per code.
But again, if that is not your case, then please disregard that last paragraph.
I hope you can solve it.
Kind regards,
Richard
HELLO I AM ABRAHAM FROM COSTA RICA I HAVE A PROBLEM WITH A TOYOTA RAV4 2002 IT IS IMMOBILIZED AND THE CAR DOES NOT HAVE AN IMMOBILIZER I WOULD LIKE TO KNOW IF THE FILE YOU HAVE SERVES ME IF HE DOES NOT HAVE IMMO
Hello Abraham. Thank you for your message.
Unfortunately no, the file is only for vehicles equipped with the immobilizer system.
Regards