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Eeprom data

Shinehead

New Member
Hi everyone, can anyone help me understand the eeprom data,what they mean and to identify if there is a problem,especially with the eeprom data on bmw frm,cas, immobelisers,identifying key data etc .
Thank you
 

rjenkinsgb

Well-Known Member
Most Helpful Member
"EEPROM" data can be absolutely anything - it's just things like settings or configuration values that need to be changeable, but not lost when power is removed.

EEPROM is electrically erasable, programmable, read-only memory.

In a car it may be used to store such as the valid remote key fobs or immobiliser RF tag numbers in the car keys etc.
Things that can be changed at times, but must never be lost if the battery is disconnected.

Car modules relating to security also may all have the VIN programmed in when they are installed or changed, to prevent an immobiliser and keys from another vehicle being substituted.

It's not part of the actual software/firmware program, that would be in ROM or flash ROM, & not working data in RAM that is lost every time power is disconnected.

"Changeable, but not loosable or forgettable" it probably the best description for things stored in it.
 

narkeleptk

Active Member
Your question is too broad but I will offer you some basic information.

All of the things you listed are doable and pretty commonly worked in. My living is mostly in immobilizers, keys and ecu's so I am pretty familiar with those if you have something specific you want to ask about but if your just wanting to learn overall then its a long road of self teaching. Mostly you learn from experience and comparing files. You need to start with tools that do some of the things you want to do first, so you can use them and then compare what they have done. After awhile you become pretty familiar with the eeprom dumps and will notice faults and can repair them of pull out/change what you need with out the tools. Some good tools. Scorpio LK's Tango, Orange5, eldb's Xprog, VVDI2, KESS, KTAG, TL866, Abrites AVDI, Carprog, AutohexII. Avoid cloned tools and stick with the originals .

As an example with bmw since you named them. All CAS, CAS2 & CAS3 modules use secured 9s12 mcu's for flash and eeprom. They are pretty basic once you bypass the security of the 9s12 mcu. The data your looking for (VIN,ISN,IMMO,Sync data, etc) are not encrypted at all. The newer CAS3+ / CAS4 do have some extra encryption but can easily be decoded by pulling additional information from DME or a working key.

The FRM's I haven't done a whole lot with but mostly for these its always a problem resetting the fault counter or a problem with the emulated eeprom getting wiped out. Usually you can retrieve it and redo it from pulling the D-flash. Many rebuild them manually from experience, I just use special software on these tho.
 
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Shinehead

New Member
Your question is too broad but I will offer you some basic information.

All of the things you listed are doable and pretty commonly worked in. My living is mostly in immobilizers, keys and ecu's so I am pretty familiar with those if you have something specific you want to ask about but if your just wanting to learn overall then its a long road of self teaching. Mostly you learn from experience and comparing files. You need to start with tools that do some of the things you want to do first, so you can use them and then compare what they have done. After awhile you become pretty familiar with the eeprom dumps and will notice faults and can repair them of pull out/change what you need with out the tools. Some good tools. Scorpio LK's Tango, Orange5, eldb's Xprog, VVDI2, KESS, KTAG, TL866, Abrites AVDI, Carprog, AutohexII. Avoid cloned tools and stick with the originals .

As an example with bmw since you named them. All CAS, CAS2 & CAS3 modules use secured 9s12 mcu's for flash and eeprom. They are pretty basic once you bypass the security of the 9s12 mcu. The data your looking for (VIN,ISN,IMMO,Sync data, etc) are not encrypted at all. The newer CAS3+ / CAS4 do have some extra encryption but can easily be decoded by pulling additional information from DME or a working key.

The FRM's I haven't done a whole lot with but mostly for these its always a problem resetting the fault counter or a problem with the emulated eeprom getting wiped out. Usually you can retrieve it and redo it from pulling the D-flash. Many rebuild them manually from experience, I just use special software on these tho.
 

Shinehead

New Member
Hi,you have answred the question 100%,thts what im exactly looking for ,since you have replied as what im looming for,my main issue is the reading of cas on bmw ,i do have some tools like ,can u help me understand the cas ,reading isn,vin ,and programming them and also writting new keys to it etc ?
 

narkeleptk

Active Member
what tools are you trying to use currently?
The location of the data varies throughout the different versions are you working on one specific right now
 
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Shinehead

New Member
Hi,sorry for late reply ,currently i use clone tools like ktag,kess,xprog, i am planning to buy the bmw cgdi for bmw,but i need to properly understand how to see and repair faulty cas data,syncronise ,bypassing security and stuff like tht,
Kind regards
 

narkeleptk

Active Member
I would not buy the cgdi.Xhorse is bringing a new vvdi BMW tool out that's supposed to be a little bit better than the BMW software for vvdi2.
 
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