A Brief Discussion on Common EEPROM Chips in Automobiles

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A Brief Discussion on Common EEPROM Chips in Automobiles [Copy link]

The common EEPROM chips in cars are classified by their interface methods, which are nothing more than I2C, Microwire, and SPI. However, each chip is divided into various capacity specifications. For example, 24C01, 24C02, and 24C04 in I2C generally have larger capacities than smaller ones, and they have a direct multiple relationship.

Among them, the types of chips used in car audio are the most numerous and the most complex, from 24C01-24C16 in I2C, 93C06 to 93C56 in Microwire, and the current audio also uses SIP's 25160. In addition, the 93C46 series of Microwire is divided into standard and non-standard. The two are mainly reflected in the pin distribution, and their internal functions are basically the same. They must be carefully distinguished when used, otherwise the data cannot be read or written and the chip is mistakenly considered to be damaged. This chip is mainly used in the car audio of the United States, and the audio of Europe and the United States basically does not use this "non-standard" chip. There are also S130 and S220 chips, which correspond to 93C46 and 93C56 respectively. In European audio systems, 85C52 chips are often seen. They are usually SMD packages, and their appearance is wider than that of general SMD chips. They are basically the same as 24C02, but the potential state of the write protection pin of its 7th pin is opposite to that of the write protection pin of 24C02. 85C52 is effective at high potential. BAW574252 is also commonly seen in older Mercedes-Benz audio systems. It is the same as 24C01. Some chips of 24C01 can read but not write data. In this case, a new 24C01 or 24C02 can be used instead. 24C02 is fully compatible with all functions of 24C01.

The chips used in LCD meters are relatively more standardized. Most of them use Microwire, from 93C46 to 93C86. There are basically no "non-standard" chips, and most of them use 16-bit structure. When reading data, you must pay attention to whether it is 16-bit or 8-bit, otherwise the high and low bits will be reversed or even the data will be wrong. This is something that you must pay special attention to when adjusting the meter. 24C04 and B58 chips are also common in new Mercedes-Benz. B58 can be replaced by 93C56. But when reading and writing data, the seventh pin must be set to a low potential. Slightly older BMWs often use CS56 and CS66, which also need to set the seventh pin to a low potential. Domestic meters also use SPI's 25010 and X25043 (X5043). Shanghai Buick and Shichao use ATMEL68343A, which is actually 25010. Toyota's 4700 Jeep also uses S220, which is equivalent to 93C56.

There are several types of anti-theft chips in Volkswagen's body, including 93C46, 93C56, and 93C86. Among them, the imported old Audi uses 93C46 (8bit), the Shichao uses 93C56 (the old one uses 8bit, the new one uses 16bit), and C5A6, PASSAT, BORA, etc. use 93C86 (16bit).

In addition, these chips are also used in airbag computers, gearbox computers, and remote door lock computers. In many unavoidable situations (such as gearbox lock, no original diagnostic computer), we can also perform maintenance work by directly reading and writing EEPROM data.

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