[tonemoz]

Hi,

Everytime I unlock used Fem with Autohex option 3, unlock Fem and reset mileage without working key or isn, after fitting Fem to vehicle and programming a new blank 434mhz key, there are no remote funtions-ie car will only start via emergency coil and key not detected in car. This only seems to happen with 434 keys. Last Fem I converted to 868, replaced receiver and programmed new 868 key, all worked fine.

Support say it's strange, has anyone else seen the same problem?


Thanks in advance.

[Mwahab]

Virgin keys with hexprog then sync again, if it didn't work try another 434 file till it work

[tonemoz]

Yeah, did reset the key and programmed again, still no joy. How to use a different key file when resetting with hexprog?

[laquangksxd]

check the frequency of the key, try with another key. You also need to check the frequency of the fem and reciver. Key problem is common with keyfob from China or key oem renew

[tonemoz]

So, just to explain a little further, the remote keys work fine with an Fem that has been unlocked using a working key, ie adding a second remote. The problem is when unlocking Fem that has no working key ie fitting a used Fem.

[Inerceptor]

When unlocking with a working key - the crypto key is calculated from key.
In the variant "all keys are lost" it is necessary to generate a crypto key using isn DME and isn FEM.
this is EWS5-crypto system.

[BmwMerc]

I had the same problem on the 868mhz FEM AKL. Keys weren`t recognised only lock/unlock worked and tried two or three different OEM remotes unlocked by Hexprog. Finally gave up on it and found a new FEM with original pre programmed keys. Support had no idea what`s going on. I think there are some issues definitely.

[Inerceptor]

There may be several situations:
1. incorrect FBD renew files, for cas4, for example (then the tool turns off the bdc/fem crypto mode)
VVDI 2 sees the incompatibility of the new key and warns before recording that the car will only be able to start through the emergency coil.
2. Incorrect/missing calculation of the crypto key from BDC/DME
3.The problem of the tool which the operation is performed. Saw this too. I had to manually return the EBC5 crypto mode and recalculate the crypto key. And everything began to work.

[tonemoz]

When unlocking with a working key - the crypto key is calculated from key.
In the variant "all keys are lost" it is necessary to generate a crypto key using isn DME and isn FEM.
this is EWS5-crypto system.

So after unlocking without working key, then matching Dme and Fem isn and programming new blank key should create crypto key? Or do I misunderstand?
Also, is there less security with 868 keys, as I said in first post, after converting to 868 all worked fine.
Is there a flaw in the tool?

[Mwahab]

I just re-read the post, so you basically unlocked FEM without DME ISN or working Keys? Thats emergency start mode .. whats happening with you is completely normal.