08 Volvo XC70 CEM replacement

[MV auto]

Hey guys!
I have a CEM to replace (with a used one) on a 2008 volvo XC70.
Replacement module have same part number, but as per scrapyard, it comes from a 2010 V70.


Part number: 7G9T-14C256-FA
I opened the original module, separate both board because memory was in sandwich between both board and could not be reach otherwise, and I found a M32C Renesas processor with what seems to be a 25LC320 just beside.

I have read/verify eeprom and Renesas with success, and I have transfer both dump in the new module. (didn't separate both board on the "new" one, as I find the pads in the back of the board to read and write both MCU and eeprom without disassembling the unit)

problem is that I have installed the new unit in vehicle, and nothing power up... not even the headlamp when you turn them on.
before I transfer the dump, my customer told me he installed the new unit and key was not catching in "ignition switch". it was pushed back.
with the transfer done, now the key catches in ignition switch, but is unable to get out of it. stuck there.
will not switch ignition on, nothing is working in the vehicle... seems to me like if the flash would have been corrupted????
when I installed back the original unit, the key was able to get in and out of the ignition switch and vehicle still start. so at least my original module is still ok.

both dump of both module read and verify ok, and after I wrote the new dumps, they verify ok.

someone have already achieved to transfer memory in those type of CEM?
anyone have any input on this one?
many thanks for your help guys!

[vanos batam]

Attatc photo of the BCM..
Maybe i have full dump.

[MV auto]

Attatc photo of the BCM..
Maybe i have full dump.

here are a few pictures + the connexion in the back of the board + full dump of both module.

as I understood, eeprom is encrypted and you cannot just swap eeprom memory. you also have to swap the matching flash dump. am I right to say that?

[vanos batam]

here are a few pictures + the connexion in the back of the board + full dump of both module.

as I understood, eeprom is encrypted and you cannot just swap eeprom memory. you also have to swap the matching flash dump. am I right to say that?

iam sorry
i dont have this
you may ask ​lupu_sandu

[kaponne]

Hello Everyone,
I'll continue this thread.
Maybe anyone have experience with 6G9T-14C256-HF 30786819 AA. How to connect the pads in the back of the board to read 25LC320.
6G9T-14C256-HF 30786819 AA.JPG

[GameTheoryOptimal]

look at post #3 buddy!

[kaponne]

look at post #3 buddy!

Hi,
Thanks for fast reply. I saw it I tried it with 7G9T-14C256-FA. It works .
But 6G9T-14C256-HF have otherness. See attached picture.
P.s. pictures not mine.


cem-0-8206896870210193519.jpgcem-1-9147103531029263017.jpg

[GameTheoryOptimal]

than you'll probably have to do R&D on your own...
or wait for someone who has done one of those.

[Dani1979]

here are a few pictures + the connexion in the back of the board + full dump of both module.

as I understood, eeprom is encrypted and you cannot just swap eeprom memory. you also have to swap the matching flash dump. am I right to say that?

Hello my freind you only take eeprom out off the cem board and copy flash from the old original part to second used part and install original eeprom to new CEM unit and car start push thanks after starting car.

[kaponne]

Hello my freind you only take eeprom out off the cem board and copy flash from the old original part to second used part and install original eeprom to new CEM unit and car start push thanks after starting car.

Why do not help just copy FLASH and EEPROM?

[Dani1979]

You must copy flash in this CEM CONTROL model the older model don't need flash memory but this model yes you must do it as I say because VIN number

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[Dani1979]

And my friend you must take out the eeprom and do it outside or put the original eeprom on new part and car start

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[kaponne]

And my friend you must take out the eeprom and do it outside or put the original eeprom on new part and car start

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Do you mean read EEPROM on board will be incorrect? Or it depends from EEPROM readers ?

[Dani1979]

Yes if you read the eeprom dump you crash starting file and if you not copy original flash to next part you will have airbag problem deferental 4?4 problem radio problem and many ecu don't conect to CEM again

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[kaponne]

Yes if you read the eeprom dump you crash starting file and if you not copy original flash to next part you will have airbag problem deferental 4?4 problem radio problem and many ecu don't conect to CEM again

Sent from my SM-G900F using Tapatalk

Can I eeprom out, make a copy and put copy to second unit?