Many people asked us how to use immo off dumps or files or immobilizer softwares like Immo ecu decoding, Immo Killer v1.1, Immo decoding tool or Immo Tool software.

In order to fulfill these requests, we will publish this basic immobilizer reset procedure by using external tools. This procedure will also apply for Toyota Virgin Dump, which is a group of dumps, as they were “dumped” out of the chip containing it by EEPROM programmer to read such contents and not generated in any other way and also for the Toyota Corolla file and Toyota RAV4 File.

The automotive immobilizer system use digital codes and transponder key data, they are all encrypted to allow the system to recognize the vehicle owner’s ignition keys and disallow the engine to start with any key. Data used for such process is stored in a memory chip, many times stored in a serial EEPROM, located internally or external to the engine Control Module.

In most cases, the chip used as storage memory is an SMD serial EEPROM of one of the following families:

  • 24C0x (example: 24C02 or 24C04 or 24C08, etc.)
  • 250xx (example: 25020 or 25040 or 25080, etc.)
  • 93Cxx (example: 93C46 or 93C56 or 93C66, etc.)
  • 950xx (example:  95020 or 95040 or 95080, etc.)

All those above, are 8-leads memory chips, around 5mm x 4mm and the differences between them are memory size, algorithm of communication, speed in KHz and MHz, voltage, temperature and some other factors. All you need to know about them is how to configure your programmer so you can read and write them. To reset immobilizer you will only read and/or write the data inside them.

There are some cases where the immobilizer data is not stored in a serial EEPROM, because it is stored in the main chip, which contains the ecu software. That type of chip, can be a separate chip in the circuit board or can be part of the Micro Controller Unit. This cases are not covered in this article, only cases with serial EEPROM as storage.


For the programmer (device or EEPROM programmer), you can use any available, if it supports the serial EEPROM(s) you will be working with. There are many not expensive equipment for working and it is fine to buy them, but if you want to doing this often, the best investment is to buy a programmer that supports as many as possible EEPROM families, with the possibility of upgrading or updating. I have been asked many times about the Willem programmer. There are many versions of programmer like Willem and it’s quite economical. If you are going to invest in programmer, first make sure that it supports your devices by checking its compatible devices list or by contacting the manufacturers. I can not give my opinion here on Willem, because I do not have any personal experience with that brand, but it seems to be prefered by many car services.

In next post we will show you more programmers and talk about immo off files.