93C46 and 93C56 EEPROM

I tore apart my instrument cluster for my 2008 Toyota Corolla made in 2007 in Cambridge, Ontario, Canada and pcb location: IC6=EEPROM is a surface mounted device with part # of 93C46W7, some claim the EEPROM out of a Camry part # 93C56 will allow odometer to roll over 299 999 KM or miles. The data sheet for both is below:


Anyone know if the Camry one will work on my Corolla?. And which EEPROM reader/writers do you all recommend I purchase that will allow me to read the old values of the old EEPROM and program the new EEPROM from a Camry # 93C56 which I will purchase from Digi-Key?. Again both of these EEPROMs are surface mounted devices, not through hole. I am an electronics engineering technician by trade and have no problem soldering out the chip and soldering in a new one but software was always my weakness.

For those of your not familiar with I am doing, for the North America market ALL:

2003-2008 Toyota Corolla
2003-2008 Toyota Matrix
2003-2008 Pontiac Vibe
2004-2005 Toyota Prius

when the odometer reaches 299 999 KM or miles it stops, and will not roll over to 300 000 KM or miles but if you read the EEPROM it continues to count true mileage but display only shows 299 999. Summary: I would like to know if I purchase from Digi-key a 93C56 EEPROM to replace my Corolla 93C46 EEPROM if the odometer will roll to 300 000 KM or miles and continue to count. Also which EEPROM reader/programmer do you all recommend that allows to interface with a surface mounted device (not through hole).

Thank you in advance for help/replies.

Dartmouth, Nova Scotia

Hello @sidney,

Welcome to the forum community! For this application, I would have to recommend you contact Toyota for their recommendation on a fix for this.

Thank you!

Toyota is in DENIAL of this issue and when cornered they would install a new instrument cluster, they will not sell you the part, they want to install it. Toyota nor any other car manufacturer ever goes down to component level to repair a problem, like electronic components.

Hello sidney,

Thank you for your correspondence. Being that the EEPROM continues to count true mileage, replacing or reprogramming the EEPROM does not appear would be the solution as it would seem the display itself or the circuitry inside the display is what is stopping the count, which may be something you might be able to troubleshoot. Unfortunately, DigiKey does not have any manufacturer documentation on the display or how to repair it from stopping the count at that set value. The only suggestion I would have to offer would be to troubleshoot the display to figure out why that is not accepting new count values, or of course, to have Toyota install a new instrument cluster.

Sorry we couldn’t be of more help on this issue. Please let us know if we can be of further assistance.



to my knowledge, STM is offering their E²PROMs only directly to their OEM’s to count true mileage upwards only - based on the SPI bus e.g. as M35080 version.
In summary: I would say that you cannot purchase these custom-specific parts from Digi-key, just their standard versions as M93C46-RMN3TP/K and/or M93C56-RDW3TP/K.