Hello Friends.

I have a 2011 535xi with Comfort access and faulty CAS. I can still communicate with CAS through OBD.
I find a used CAS from a 2018 X4 with Comfort access and most likely has different MASK and EWS5.
What is the correct procedure to replace CAS in this case?

Should i read dump of 2018 CAS4 and zero out mileage and then use autohex to replace CAS?

If it's communicate then try to reprogram it, unless it's hardware damaged.

already tried reprogramming several times. there is a hardware problem.

okay so i read the original CAS and it had a 1N53H mask rom, can i write this flash in to donor CAS with 5M48H mask rom?

The original CAS contents were not encrypted. I was able to read ISN and the decrypt button was greyed out.
The Donor CAS content were encrypted and i do not have a matching key for that CAS.


Thanks!

As the Cas files are the same size it is possible to transfer the data from cas4 to cas4+ even for the above-said mask. HexProg can write data if the data size is the same for the cas4/cas4+.

Thank you. I will try and report back

i was able to find an exact CAS so i cloned it instead with the same Mask.

I did recheck the written data and it is not 100% the same. I tried a few times and each time hexprog changes the data.

For example. The VIN is ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ instead of the correct VIN. When i change the VIN to the correct VIN, it does store it correctly.

Is this normal operation for hexprog?

Hope you have latest version of hexprog software, vin and other major data must write correctly on cas4. some minor portions may be different but will not cause the operation on the car.

thank you. Hexprog is up to date.
I found the problem. The used CAS was faulty too. Same part number.
I ended up cloning to the latest version part number and the VIN was written correctly the first time.

I think if anyone in the future has similar issue, its a bad CAS.