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All keys lost CAS3++ downgrade dump question - Printable Version

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All keys lost CAS3++ downgrade dump question - willisodhiambo - 16-04-2019

I am thinking this way. In an all keys lost for CAS 3++ situation, without an expensive tool, would it not be possible to write a dump, that is obtained from a similar cas downgraded by say Autohex, cgdi or other?.

Make key with the downgraded dump, then update with winkfp and attempt a start?

I ask because I have yanhua mini, which does not have cas downgrade option. I doubt it can make a working key for a crypto cas 3++.

What exactly does downgrading do? Flash eeprom/flash with an older non crypto version? If I has a dump of this older version, could i not use it in all such situations with a programmer, make key then update?


RE: All keys lost CAS3++ downgrade dump question - rs@chip - 16-04-2019

Teoreticly yes but is not such problem anymore, downgrade Is used when you do keys obd if you do by dump no need for ,on encripted cas you need dme code as well


RE: All keys lost CAS3++ downgrade dump question - RocketSurgeon - 16-04-2019

Encrypted CAS requires either key or ISN to decrypt, regardless of downgrade.
Simply writing a different dump would be problematic because you would be changing the CAS ISN and the car would not start.
I prefer to do encrypted CAS keys from dump, rather than downgrade. Process is much safer, especially with Chinese tools.


RE: All keys lost CAS3++ downgrade dump question - tomushas - 16-04-2019

(16-04-2019, 03:28 AM)willisodhiambo Wrote:  I am thinking this way. In an all keys lost for CAS 3++ situation, without an expensive tool, would it not be possible to write a dump, that is obtained from a similar cas downgraded by say Autohex, cgdi or other?.

Make key with the downgraded dump, then update with winkfp and attempt a start?

I ask because I have yanhua mini, which does not have cas downgrade option. I doubt it can make a working key for a crypto cas 3++.

What exactly does downgrading do? Flash eeprom/flash with an older non crypto version? If I has a dump of this older version, could i not use it in all such situations with a programmer, make key then update?
Have you cas dumps.? attach here


RE: All keys lost CAS3++ downgrade dump question - willisodhiambo - 17-04-2019

(16-04-2019, 17:46 PM)RocketSurgeon Wrote:  Encrypted CAS requires either key or ISN to decrypt, regardless of downgrade.
Simply writing a different dump would be problematic because you would be changing the CAS ISN and the car would not start.
I prefer to do encrypted CAS keys from dump, rather than downgrade. Process is much safer, especially with Chinese tools.

Aha. So as long as i can get dme isn the Chinese tool will likely succeed make a working key. Thanks


RE: All keys lost CAS3++ downgrade dump question - psya - 17-04-2019

Write a Flash and eeprom dump to a new cas.
Read out ISN from DME and write in new CAS
Make key for cas3
Job done

Or Get a cas3 with working key, change ISN in cas with ISN from DME, start car.


RE: All keys lost CAS3++ downgrade dump question - willisodhiambo - 18-04-2019

(17-04-2019, 12:56 PM)psya Wrote:  Write a Flash and eeprom dump to a new cas.
Read out ISN from DME and write in new CAS
Make key for cas3
Job done

Or Get a cas3 with working key, change ISN in cas with ISN from DME, start car.

Yes this is best approach, it is just that I don't trust my Chinese tool 100% for cas crypto. I renewed ICP this way by changing dme isn in cas with Yanhua mini then compared to what autohex had done on the same cas. The two dumps compared have several differences!! Which means one tool is not 100% accurate.


Did not try either solutions on the car because owner found the lost key just before I could implement. Will do an experiment if I get my hands on an E series.