ISN read from EDC16C35

vladys said:

I need help reading ISN from eeprom or full data, (not working with CAS3 V1,3 ) I managed to extrac...

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• Bosch HW number: HS1037500774
• SW number: 1037376616
• Production dates: 24-08-09 / 27-08-09

0x40: 00 00 C1 E7 A3 38 4C 9F 18 B7 2C F0
0x80: 00 00 C1 E7 A3 38 4C 9F 18 B7 2C F0
0xC0: 00 00 C1 E7 A3 38 4C 9F 18 B7 2C F0

1. A tool that can read ISN via K-Line/OBD diagnostics from the DDE while powered (e.g., INPA with the correct script, Autohex II, AVDI, Yanhua ACDP, etc.)
2. A tool that can decrypt the EEPROM ISN blocks using the known algorithm for EDC16C35 (Yanhua ACDP Module 27, Autohex II, or similar)

• Use the donor CAS + donor DDE together
• Program a new key to the donor CAS (Yanhua ACDP, Autohex, Xhorse VVDI, or even your Launch X431 if it supports CAS3++ key learning)
• Code/program the donor DDE VIN to match your car's VIN (via ISTA/P or WinKFP)

• Read the ISN from your original DDE via OBD (K-Line, pin 7+8) using a tool that supports EDC16C35 ISN read — Yanhua ACDP Module 27 or Autohex II can do this directly
• Write that ISN into the donor CAS3++
• Program a new key to the donor CAS

• Clear/virginize the ISN in the DDE EEPROM (write known virgin ISN pattern)
• Clear ISN in the CAS
• Let them sync on first start via ISTA/P

• Does the donor CAS3++ and donor DDE come from the same donor car?
• Do you want to keep your original DDE or are you okay using the donor DDE?
• What is the exact CAS3++ part number on both units (original and donor)?

Gemini said:

Looking at your EEPROM dump, I can extract some useful information for you.

From the EEPROM (8KB) analysis:

The ISN in EDC16C35 is stored in the external EEPROM, specifically in the encrypted blocks starting at offset 0x40. Looking at your dump:

• Bosch HW number: HS1037500774
• SW number: 1037376616
• Production dates: 24-08-09 / 27-08-09

The ISN-related data in EDC16C35 is stored in the EEPROM area around offsets 0x40–0xBF. In your dump I can see three encrypted ISN blocks (each 32 bytes), all sharing the same first 10 bytes:

Code:

0x40: 00 00 C1 E7 A3 38 4C 9F 18 B7 2C F0
0x80: 00 00 C1 E7 A3 38 4C 9F 18 B7 2C F0
0xC0: 00 00 C1 E7 A3 38 4C 9F 18 B7 2C F0

This is good — the ISN blocks are consistent and not corrupted. However, the ISN in EDC16C35 is AES-encrypted in the EEPROM. You cannot simply read it as plaintext from the dump. The raw ISN is encrypted with a key derived from the Bosch internal flash, so extracting the actual ISN value from a dump alone requires either:

1. A tool that can read ISN via K-Line/OBD diagnostics from the DDE while powered (e.g., INPA with the correct script, Autohex II, AVDI, Yanhua ACDP, etc.)
2. A tool that can decrypt the EEPROM ISN blocks using the known algorithm for EDC16C35 (Yanhua ACDP Module 27, Autohex II, or similar)

Your real problem and the practical path forward:

Since your original CAS3++ ISTAP is corrupted (reading FFFFF... for ISN), and you have a second donor CAS3++ + DDE from the same model (525d 3.0 E60 LCI 2009), you have a few options:

Option A — Sync donor CAS + donor DDE (easiest):
If the donor CAS3++ and donor DDE came from the same car, they already share the same ISN. You would:

• Use the donor CAS + donor DDE together
• Program a new key to the donor CAS (Yanhua ACDP, Autohex, Xhorse VVDI, or even your Launch X431 if it supports CAS3++ key learning)
• Code/program the donor DDE VIN to match your car's VIN (via ISTA/P or WinKFP)

Option B — Read ISN from your original DDE and write it to the donor CAS:

• Read the ISN from your original DDE via OBD (K-Line, pin 7+8) using a tool that supports EDC16C35 ISN read — Yanhua ACDP Module 27 or Autohex II can do this directly
• Write that ISN into the donor CAS3++
• Program a new key to the donor CAS

Option C — Virginize/clear ISN on both and re-sync:

• Clear/virginize the ISN in the DDE EEPROM (write known virgin ISN pattern)
• Clear ISN in the CAS
• Let them sync on first start via ISTA/P

My recommendation:

Since your Launch X431 + X-PROG3 cannot read ISN from the dump, and the EEPROM ISN is encrypted, you realistically need Yanhua ACDP with Module 27 (BMW DME/DDE ISN read) — it reads ISN from EDC16C35 via OBD on the bench and also writes ISN to CAS3++. This is the most straightforward path for your situation.

Do NOT attempt to manually edit the encrypted ISN bytes in the EEPROM without the correct tool — you will brick the DDE.

Can you confirm:

• Does the donor CAS3++ and donor DDE come from the same donor car?
• Do you want to keep your original DDE or are you okay using the donor DDE?
• What is the exact CAS3++ part number on both units (original and donor)?

This will help determine the simplest path to get your car running.

Click to expand...

• YES the donor CAS3++ and donor DDE come from the same donor car , The donor car is not SE BUS EDITION like my car and with the Option A the car starts and runs but it gives me many errors on the dashboard.. I'll try option B and tell you what I solved.
• 
  
• Do you want to keep your original DDE or are you okay using the donor DDE?Answer :I'm just interested in making the car run without errors so I can pass the Periodic Inspection.
• What is the exact CAS3++ part number on both units (original and donor)?
• Answer:I atached photos
• Thank you in advance

vladys said:

ISN from DDE : C1E7 ?

I confirm:

YES the donor CAS3++ and donor DDE come from the same donor car ,...

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• CAS3: 61.35-9217853-01 — Siemens VDO 5WK4 9515ABR — HW C4, SW 20.0, Cod 09, Diag 06A0, FSV 2.5.2, OSV 3.3.0
• DDE: 8 509 034-01 — Bosch 0 281 016 638 — dated 09-08-27

• CAS3: 61.35-6943834-01 — Siemens VDO 5WK4 9513CBR — HW C4, SW 12.5, Cod 08, Diag 06A0, FSV 1.7.5, OSV 3.3.0
• DDE: 7 806 987 — Bosch 0 281 014 436 — dated 07-07-07

Critical difference between the two CAS units

1. Software version mismatch — the donor CAS FSV 1.7.5 is too old for your LCI car's module network. Your car expects CAS FSV 2.5.x.
2. FA/VO (vehicle order) mismatch — your car is SE BUS EDITION, the donor is not. Different equipment coding = different module expectations.
3. VIN mismatch — all modules on the bus check VIN consistency.

• Read the EEPROM from your original CAS3++ (the chip is a D80/D160 flash inside — your X-PROG3 should support reading CAS3++ on bench)
• Write the correct ISN C1E7 into the CAS EEPROM at the ISN location
• The ISN in CAS3++ is stored as a 16-byte (128-bit) value. For EDC16C35, the short ISN is C1E7 but you need to write the full 16-byte ISN. The BMW-AZ tool you used shows "Edit 16 byte ISN" button — click that to see if it gives you the full 16-byte value from the DDE EEPROM.

About the ISN "C1E7"

• The short ISN for EDC16 is typically 2 bytes (4 hex digits) = C1E7
• But CAS3++ uses a 16-byte (128-bit) ISN for the synchronization
• The full 16-byte ISN needs to be derived/calculated — the BMW-AZ tool should show this when you click "Edit 16 byte ISN"

1. Click "Edit 16 byte ISN" in the BMW-AZ tool and screenshot the full 16-byte ISN value
2. Read your original CAS3++ (9217853) EEPROM with X-PROG3 and upload the dump — I can check if the ISN area is truly corrupted or recoverable
3. Confirm: does your Launch X431 have the option to write ISN to CAS3++?

vladys said:

The software doesn't show me the 16 bit ISN when I click "Edit 16 byte ISN" in the BMW-AZ tool
Can ...

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00000000  53 b1 C1 E7 ac ff ff ff 6e 7a 46 98 ff ff ff ff
00000010  00 00 C1 E7 a8 ff ff ff 00 00 C1 E7 ff ff ff ff
00000020  a2 61 5b 78 ff ff ff ff 00 00 C1 E7 ff ff ff ff
00000030  98 f8 cf 27 ff ff ff ff 2a cf f8 07 ff ff ff ff

• The tool was reading the wrong area, or
• The tool expects the ISN in a different format/location for CAS3++ ISTAP, or
• The D-flash (flash memory, not EEPROM) of the CAS was corrupted by the person who tried to program a key

• Key 1: 012B — status byte 01 = key is active/learned, type 2B. This is your working key.
• Key 2: 004B — status 00 = learned but may need sync, type 4B
• Key 3: 004B — same, learned
• Key 4: 004B (in keie4.bin) or 0076 08 FFFFFFFF (in others) — varies between your save attempts
• Keys 5–10: 007608FFFFFFFF — these are empty/unlearned key slots

00 00 C1 E7 A3 38 4C 9F 18 B7 2C F0

1. The key learning data was corrupted (keys were partially overwritten)
2. The CAS key counter or authentication state was corrupted
3. The CAS software (D-flash) was partially corrupted during an interrupted flash

• Write back the clean EEPROM backup (eprombmw525.bin) to the CAS EEPROM chip
• Write back the clean flash backup (flashbmw525.bin) to the CAS D-flash
• This should restore the CAS to the state it was in when you made these backups

• If you still have the physical keys that correspond to Key 1, 2, or 3 — try them. Key 1 (status 01, type 2B) should be the primary working key.

• Use your Launch X431 to program a new key to the original CAS3++
• The ISN is C1E7 — your Launch should be able to use this for key learning
• Since the CAS already has the correct ISN matching the DDE, once a key is learned, the car should start

• Both have matching ISN, matching VIN, correct FA/VO for your SE BUS EDITION
• No coding errors, no module mismatch

Gemini said:

Excellent work, you have very good backups. Let me analyze everything in detail.

CAS3++ EEPROM Analysis (eprombmw525.bin / eprombmw2.bin)

Both CAS EEPROM files are identical — good, consistent reads.

Looking at the ISN area in the CAS EEPROM (offset 0x00–0x3F):

Code:

00000000  53 b1 C1 E7 ac ff ff ff 6e 7a 46 98 ff ff ff ff
00000010  00 00 C1 E7 a8 ff ff ff 00 00 C1 E7 ff ff ff ff
00000020  a2 61 5b 78 ff ff ff ff 00 00 C1 E7 ff ff ff ff
00000030  98 f8 cf 27 ff ff ff ff 2a cf f8 07 ff ff ff ff

Great news — your original CAS3++ is NOT fully corrupted! The ISN C1E7 is clearly present multiple times in the CAS EEPROM at offsets 0x02, 0x12, 0x16, 0x22, and 0x2C. The ISN storage in this CAS is intact.

The reason your tool was reading "FFFFF..." was likely because:

• The tool was reading the wrong area, or
• The tool expects the ISN in a different format/location for CAS3++ ISTAP, or
• The D-flash (flash memory, not EEPROM) of the CAS was corrupted by the person who tried to program a key

CAS Flash Analysis (flashbmw525.bin / flash2bmw.bin)

Both flash dumps are also identical — good. This is the 512KB D-flash (D80/D160 processor internal flash). This contains the CAS operating program. The data looks valid (not erased, not all FF).

Key Data Analysis

From your key data files, I can see:

• Key 1: 012B — status byte 01 = key is active/learned, type 2B. This is your working key.
• Key 2: 004B — status 00 = learned but may need sync, type 4B
• Key 3: 004B — same, learned
• Key 4: 004B (in keie4.bin) or 0076 08 FFFFFFFF (in others) — varies between your save attempts
• Keys 5–10: 007608FFFFFFFF — these are empty/unlearned key slots

The FFFFFFFF in the key data after 007608 means those slots have no transponder data — they are blank. You have 3 keys programmed (Key 1, 2, 3) and possibly Key 4 in one of the saves.

DDE EEPROM Confirmation

The DDE EEPROM is identical to what you shared before. ISN at offset 0x42–0x43 = C1 E7. The full encrypted ISN block at 0x40:

Code:

00 00 C1 E7 A3 38 4C 9F 18 B7 2C F0

This 10-byte sequence matches between CAS and DDE — both units share the same ISN. Your original CAS and original DDE are already paired.

VIN from CAS EEPROM

From the printable strings in the CAS EEPROM: WBANX52050C292056
sеriаl: 292395565
Date: 08092009

So What Actually Went Wrong?

Your original CAS3++ ISN is NOT erased. The C1E7 is there. The problem the previous person caused is likely one of these:

1. The key learning data was corrupted (keys were partially overwritten)
2. The CAS key counter or authentication state was corrupted
3. The CAS software (D-flash) was partially corrupted during an interrupted flash

Your Action Plan

Since the ISN matches between your original CAS and original DDE, you do NOT need to transfer any ISN. You need to:

Step 1: Restore your original CAS3++ to working state

• Write back the clean EEPROM backup (eprombmw525.bin) to the CAS EEPROM chip
• Write back the clean flash backup (flashbmw525.bin) to the CAS D-flash
• This should restore the CAS to the state it was in when you made these backups

Step 2: Try your existing keys

• If you still have the physical keys that correspond to Key 1, 2, or 3 — try them. Key 1 (status 01, type 2B) should be the primary working key.

Step 3: If no existing key works — program a new key

• Use your Launch X431 to program a new key to the original CAS3++
• The ISN is C1E7 — your Launch should be able to use this for key learning
• Since the CAS already has the correct ISN matching the DDE, once a key is learned, the car should start

Step 4: Install original CAS + original DDE in the car

• Both have matching ISN, matching VIN, correct FA/VO for your SE BUS EDITION
• No coding errors, no module mismatch

About the 16-byte ISN

For your specific case, you don't need the 16-byte ISN because your CAS and DDE are already matched. The 16-byte ISN is only needed when you want to write a new ISN into a CAS from scratch (e.g., when using a donor CAS). Your original pair is intact.

The short ISN C1E7 is what the Launch X431 needs for key programming. When it asks for ISN, enter C1E7.

Do you still have the original physical keys (the ones that were working before the CAS was corrupted)? This is important — if you have them, restoring the EEPROM backup should make them work again immediately.

Click to expand...

vladys said:

In slot 2,3,4 I tried to make new keys, I still have them physically, but they didn't work when I ma...

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• Key 1: 012B — Active, working original key
• Key 2: 004B 0030B23A97 — Learned key (your first attempt)
• Key 3: 004B 002DE53A97 — Learned key
• Key 4: 0076 08 FFFFFFFF — Empty slot (no transponder written yet)

• Key 4: 004B 00B9FC1E97 — Now learned

• Key 2: 004B 00864F9997 — Different transponder data than before (reprogrammed)
• Key 4: 004B 00B9FC1E97 — Same as before
• Key 5: 005B 00864F9997 — Same transponder as Key 2 (duplicate/copy attempt)

• Key 2: 0076 08 FFFFFFFF — Erased back to empty
• Key 4: 004B 00B9FC1E97 — Still there

• Your new keys were programmed (status 004B = learned)
• The DDE ISN matches the CAS ISN (C1E7)
• But the car still won't start — because the ELV refuses to unlock

• Connect to the car with ISTA/P or Tool32
• Use the CAS function "ELVRESET" or "steuernelv_nachtransport"
• This requires a valid key in the CAS that can authenticate

• If the ELV is permanently locked and cannot be reset, you can install an ELV emulator (also called ELV repair module)
• These are small modules that replace the ELV and always respond "unlосkеd" to the CAS
• For E60 CAS3++ this is a common solution — search for "BMW E60 ELV emulator" or "BMW ELV repair"
• Cost is typically 30–80€

• Some specialists can repair/reset the ELV module on bench
• They read the EEPROM from the ELV motor unit and reset the lock counter

• If you restored the original EEPROM and you still have the original Key 1 physically (the one that was working before all this started), it should work immediately
• If you lost the original Key 1, you need to do all-keys-lost again with the Launch X431, but only after the ELV is fixed

vladys said:

ELV blocked" — the steering column stay locked.
When I install the Donor DDE +CAS donor kit. the c...

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• Your original CAS3++ + original DDE — ISN matched (C1E7), but ELV is hard-locked. Car won't start.
• Your donor CAS + donor DDE kit — working, car starts with the donor key. ELV accepts the donor CAS.
• You bought 2 new blank keys to program to the donor CAS.
• You want to program these 2 new keys to the donor kit so you have 3 working keys total.

• Reset during the donor kit installation
• Or the donor CAS ELV authentication data was written to match your car's ELV

• The donor CAS ISN — NOT C1E7 (that's your original). You need the ISN from the donor CAS.
• The donor DDE ISN should already match the donor CAS (since the kit works).

• Option 1: Read the donor CAS EEPROM on bench (same way you read your original — 93C86 chip) and I can extract the ISN for you
• Option 2: Use your Launch X431 → BMW → CAS → Read ISN (some Launch versions can read ISN via OBD if the CAS is not locked)
• Option 3: Read the donor DDE EEPROM — the ISN will be at offset 0x42–0x43 (same location as your original)

• Step 1 — Get the donor CAS ISN (using one of the methods above)
• Step 2 — Launch X431 → BMW → IMMO → CAS3++ → Add Key / All Keys Lost
• Step 3 — Enter the donor ISN when prompted
• Step 4 — Follow the procedure with the working donor key + the 2 new blank keys
• Step 5 — Test all 3 keys

• Do NOT install your original CAS back in the car — the ELV is locked against it. You would need an ELV emulator or ELV repair to use it again.
• Do NOT attempt all-keys-lost on the donor CAS without the donor ISN — you will lock yourself out.
• Use "Add Key" mode, NOT "All Keys Lost" — since you have a working donor key, you don't need AKL. Add Key is safer and won't erase the existing working key.

vladys said:

I made a second key with the donor DDE×CAS donor kit, but it shows many errors on the dashboard.

Click to expand...

• Read the donor CAS EEPROM (93C86)
• Replace the VIN in the donor CAS EEPROM with YOUR car's original VIN
• Write it back
• This makes all other modules recognize the CAS as "their" CAS

• Use ISTA/P or NCS Expert to write your car's original FA/VO into the donor CAS
• This ensures all coding indexes match your car's equipment

• After VIN correction, use ISTA/P to re-synchronize CAS with all modules
• Clear all DTCs (fault codes) from every module
• Some modules like ACSM (airbag) and EGS (gearbox) may need individual re-coding

1. Do you have access to ISTA/P or NCS Expert with an ICOM or K+DCAN cable?
2. Do you know your car's original VIN?
3. Can you upload the donor CAS EEPROM dump? I can show you exactly where to change the VIN and verify the ISN before you write it back.