How many methods to program BMW CAS 3++ key successfully?

Thanks to DK members who are talking about how to safely program CAS 3++ key. The poster consider they are very helpful and would like to share their using experience and options in this article.

How many methods to program BMW CAS 3++ key successfully

1.Use AVDI to program CAS 3++ key

Normally we get these and then remove and backup on bench before downgrading and programming a key through OBD with AVDI with 13.5v charger etc.


What are the disadvantages in this method?

Obviously don’t like downgrading as potential issues and also removes the security aspect on the car.


2.Use Tango to program CAS 3++ key

If we talking about spare key then of course read eeprom on bench is enough (working key required to decrypt ISN). If all keys lost still need downgrade or need cas eeprom + ISN from DME.

Tango always prompt to write new eeprom to CAS after key programming but you dont have to do it, unless you program new key on already used position.



I tried this today with a working key and it doesn’t work. Old key works fine, but the new one just doesn’t bring the dash on? In the end i downgraded CAS & then programmed through OBD and worked fine (obviously having a backup first.

I’ve tried it on 3 cars though so don’t think it’s my files, cause I always verify the read with VVDI prog & Tango detects it as a cas3++. It must be my keys.

Solution: I do duplicates the same way, but I use Xhorse VVDI2 programmer.


3.What is the best way of preventing the risk of CAS3++ Istap failure when programming key via OBD only? Using xhorse vvdi2 only.

Suggestions from Xhorse engineer & whom have done many VVDI2 CAS3++:

1) Continuous 13 volts with a voltage stabilizer.

2) Voltage  it’s one thing you need to consider.

3) Voltage… I done lots off them no problems

4) The voltage drop can be the reason it fails.

5) Voltage is the biggest thing. Best way to do it is on the bench to be safe.

6)  The best way to prevent an issue with the downgrade is to not do it via OBD. Or pull the CAS out and read/save the eeprom prior…. It takes 5-10 minutes to do with some practice. Read CAS with programmer .. make key .. put all back ..job done ..

7) Make backup eeprom and flash via vvdi prog programer and than do downgrade or what ever you want

Youtube search: “how to read CAS dump by VVDI PROG”

So if you need to do with VVDI2 via OBD. Go and get a battery stabilizer. It will work.

The best way is to backup eeprom and write key on bench.


4.Use CGDI BMW programmer to program CAS 3++ key

It is possible to bypass the downgrade by reading the flash and eeprom on the bench and then loading into tango programmer and programming key through that.

It’s how I used to do 9389115 before it was doable by obd. I used CGDI BMW not Tango to write the key, though. Once downgraded, you can always reflash in a couple of minutes.


5.Program CAS 3++ key without downgrading:

You can read eeprom on cas3+ or cas3/ista-p, then use programmer to make key with eeprom file. that’s how I do keys when I don’t downgrade. I don’t write back to CAS, I choose new key position.