Repair BMW CAS3+ ISTAP with Autel IM508/IM608 After Failed Update via OBD

Here comes the common problem with BMW CAS3 key programming via OBD:

BMW X1 2011 CAS3++ istap now cannot turn on with the working key. I downgraded CAS3, did put battery support on (GYS Flash) but Wifi cut out during update. And it failed now no ignition.

Here is the guide to repair a BMW or mini CAS3 module after a failed software update using the autel im508/im608.



2 Solutions:

1. Try Repair online first

2. if not success then try ECUs repair by dump



Solution 1: online repair

There is a repair option with vvdi2 via obd, worth a try first.

If not then autel has a repair option also.

Autel Im608 Repair Bmw Cas3 1 Autel Im608 Repair Bmw Cas3 2

With the im608/im508, you have the repair files, remove CAS, backup what’s left, upload to autel (via 608), receive files back (it’s instant), reinstall repair files.

Check the step-by-step guide in im608 below.

(*If all keys lost situation. It may have also lost ISN so repair will not let car start but ignition will come back. Then you need to read ECU isn and do CAS renew on autel to fix.)



Solution 2: Repair by dump

Need to remove CAS from car and read it with a programmer. NO need to replace CAS.

If you have hextag read the eeprom, put it into hexprog and it can change file to a running file write back to the eeprom, all up and running. Check: Repair BMW CAS3+ Data Corruption with Hextag

If don’t have a hextag, read with other programmer. Read with prog uploaded files to autel for CAS repair, repaired files written back with extra key added works fine.

Autel gives good fix on bench as well.




How to Repair BMW CAS3++ and Add a Key with autel maxiim im608?

Model example:  BMW X1 CAS3++ istap 2011 with Mask 0L15Y

Step 1: Read EEPROM & FLASH

Uninstall CAS box and welding cable apa109

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Left key customer key that cannot start now

Right is new key

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Connect xp400 pro and apa109 cable via USB port. The im608 has built in colored schematics with great quality pictures. Soldering is the hardest part.

(How to check wiring diagram: Go to Programmer- Chip -Chip Read & Write – Immobilizer- BMW – CAS3+ – 0L15Y -RW -Schematic diagram)

Autel Im608 Repair Bmw Cas3 3 Autel Im608 Repair Bmw Cas3 4

Select Immo- BMW- Manual Selection- X1- 2008/09-2015/06 E84 – Control unit- CAS3/CAS3+ Immobilizer -ECU operation

Follow the instructions in the help information for strict operation

Show ECUs operation guide and schematic diagram

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Select 0L15Y- Read EEPROM

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Save eerpom file, i.e BMW CAS3+_0L15Y_OM23S_EEPROM-07052021.bin

Read Flash

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Read Flash success, save flash data i.e BMW CAS3+_0L15Y_OM23S_FLASH_07052021.bin


Step 2:  ECU Repair 

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Select Special function- ECU repair- 0L15Y/0M23S

Load the EEPROM file of the current vehicle (select CAS3+_0L15Y_OM23S_EEPROM-07052021.bin read in step 1)

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The file is being modified. Save new file.

EEPROM file is saved successfully, i.e CAS3PlusEepromFileEdit-07052021.bin

Load FLASH file (select CAS3+_0L15Y_OM23S_FLASH-07052021.bin read in step 1)

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Save new flash file. i.e CAS3PlusFlashFileEdit-07052021.bin


Step 3: How to Add a New Remote Key

Next show how to add new remote

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Back to Key operation – Key Learning- Make key with file- 0L15Y/0M23S

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Load the EEPROM data, select the new FileEdit eeprom read in step 2

Verify VIN, mileage and frequency information

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Choose key position 3 and press write key

Press Add key

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Put a working key into xp400 programmer

Reading key information

Read key info successfully, proceed with the next step

Select semi smart key

Put new key into the programmer

Writing key

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Save new eeprom file

Flash the new car eeprom file into car, then use the new dealer key to start the engine.

If CAS belong to is istap version, don’t write new file back to CAS.

Go back to ECU Operation- 0L15Y -Write eeprom

Load Modify eeprom bin file

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Writing eeprom file successfully

Write flash

Load FileEdit flash file, wait 7-8mints to write flash

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Write flash successfully

Now this CAS can start engine with normal operation.


Keep in mind, it’s always a risk doing istap through obd bench is much easier and safer it was a pain to recover the files.