[kklobo]

Hi i had e93 335is form Usa with one key key randomly stopped working 
Car starts with key in slot, Comfort access not working at all, No opening and closing wia fob.

New battery same, another mirror from cabrio still not working.
Fob sending 315mhz signal both mirrors form usa and cabrio, both have 315 printed on housing. 

No errors in cas and ca module ista says after diagnosis replace mirror and next time when i select that mirror has been replaced says replace cas.
Wires from mirror to cas and ca are good i had power and ground on modules and mirror no water damage on pcb
It will be high costs to add, a key to the new CAS because I can't do it myself 
Is possible to change cas from another car without doing immo for check only that central lock working ? Or maybe i missing something.

[RocketSurgeon]

Ok, this one is a bit strange. I have seen a BMW key fail in a way that it produced a 315mhz signal, but the car did not respond. Transplanting the PCF transponder chip onto a fresh board fixed the issue. I kind of doubt your key is the issue though.

I would take a serious look at the comfort access handles. On that generation, the handles can fail in a way that they cause issues with the CAS and comfort access system without throwing codes or blowing fuses like the F-series cars. I would unplug the comfort access handles and see if radio or comfort start work.

[user0086]

Replacing CAS for testing is possible but the mileage of the car and donor CAS will be set to the highest of both, unless you remove all fuses of the KOMBI instrument

[kklobo]

I disconnect passive go ecu from car, handels are connected to this unit so i think they can't interfere anything. Still same behaviour. I got used cas ( not connecting yet).
What do now?
1 go to immo guy with old CAS new CAS and remote
2 disconnect kombi connect new CAS and code it to the car
3 disconnect kombi connect new CAS and flash cas

[RocketSurgeon]

I don't like to plug in a CAS from a different vehicle because it could roll up your mileage or install an ISN in your transmission.

My top choice is to clone the CAS with BDM process. The only issue is that you could potentially be copying a software problem onto the new module. Perhaps reflashing would fix it, perhaps not. That would solve a hardware issue though.

Are you in the continental US?

[willisodhiambo]

The new cas has its Key?
1. Disconnect Kombi and CA
2. Connect new CAS
3. Test key that came with new cas, make sure battery is OK
4. Make new key if it still does not work!!

[kklobo]

Key was damaged new kay and works fine. Buttons and ca works well
so checking key that sending something is not accurate. Case closed.