One customer added new keys to his BMW CAS4+ by CGDI BMW via OBD after preprocessing, but some fault codes were appearing, and he couldn’t start his car with the original car key and a new key, even though reprogrammed and made coding.

Here is the clue.
CAS4 is unencrypted and CAS4+ is encrypted. For example, the 5-series or 7-series models from 2009 to 12 are all CSA4 models, while the 13-16 models are CAS4+ versions. Now many tools can support new key adding via OBD. However, there is a large risk when doing CAS4 via OBD.
It is recommended that you remove the module to read the data (it’s safest), especially for the 2012 7 series F02 Chassis 6HP, it has a huge risk via OBD, and needs to remove the module to read the data for repair. CAS4+ uses OBD with a relatively small risk rate, but there are still risks.
We can solve the problem by the method below.

1. Confirm the initial anti-theft version information is CSA4 or CSA4+
This is the initial key matching screen showing the CAS4 PLUS version.
Note:
If you don't take a photo and don't remember what version this is, you have to go to the installation folder in the CGDI Prog BMW to find the document and open it. If there is a password, ISN, key synchronization code, and DME ISN then this is CSA4+. In contrast, CAS4 is two lines of code.)

2. Re-match the original car key and re-set the code
Synchronization code is lost due to the reduced version of the programming process.
We first need to know the number of key positions of the original car key, then re-match the original car key, and then re-set the code for anti-theft in the F system.
After completion, we return to the key matching interface, which has changed back to the CAS4 PLUS version.

3. Clear fault code and re-generate dealer key
After the key matching of the original car has been completed, the anti-theft code has been reset, and the version has returned to CAS4 PLUS to test whether the key is normal.
If the original car key and new key are tested fine, this time the wiper may always scrape, and the car still has a lot of fault code. Do not be afraid, the problem is not big.
We can clear the fault code once, turn off the switch, and wait 10 minutes to return to normal.
In another case, if the original car key can be normal, but the new key still cannot be started, we can manually input the ISN of the engine to generate the dealer key again.

The method for CAS4+ key problems with CGDI Prog BMW Key Programmer is the above. When you encounter such models or failures, you can solve them according to the above methods.

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