Key fob starts car, but remote won't open car

[Robotson]

Another tedious key based thread I'm afraid. I thought I'd already experienced every gamut of e46 key based trauma, but I have a new problem.. 

Car has a drain caused by something that fuse 62 is responsible for (hvac related), and this killed my battery. So badly it wouldn't even jump start. So AA just replaced the battery. 

Now, the key continues to start the car, but no longer opens (or locks) the doors with the remote. I know the keys can become out of sync with the car, as I've been through that. But when that happened to me, the car would not start with the key. 

But can anyone remember, is there 2 types of syncing? Ie one with fob to doors etc, and one with key to EWS system? 

In the past, I remember doing some sort of sync where I had to hold down buttons on the fob and turn the ignition to certain points, but then this synced the fob go the doors, but resulted in the EWS being out of sync with the fob. So at that time, I could open the car remotely but not start it. End result was £125 for a new key. 

Now I have the opposite problem. Any ideas? 

PS the AA guy tested the key and could see that it was producing a signal. So that leads me to think it is just out of sync? 

Edited January 24, 2018 by Robotson

[rasa]

battery has probably died,,plenty how to,s of how to replace them,but you have to cut them open,,i have 2 k eys and one of them is dead,,if i use car with the remote with the good battery,lock car..then go out with dead battery key,,open car..alarm goes off until i insert it into barrel,where the key syncs to car..doesnt bother me having no remote key.

Edited January 25, 2018 by rasa

[Robotson]

31 minutes ago, rasa said:

battery has probably died,,plenty how to,s of how to replace them,but you have to cut them open,,i have 2 k eys and one of them is dead,,if i use car with the remote with the good battery,lock car..then go out with dead battery key,,open car..alarm goes off until i insert it into barrel,where the key syncs to car..doesnt bother me having no remote key.

Thanks rasa. Unfortunately that fob had a new battery last summer, and the AA guy had some sort of meter that showed that it was producing a signal. 

I'm starting to think I do have to just sync it. 

I think I'm remembering now that the reason the EWS became unsynced from the key last time was that the battery from the fob was out for too long when we changed it, and the transponder lost power, so became unsynced from the EWS. I think. 

But this time I'm hoping that has not happened as the battery hasn't been out.. all that happened is the car battery died. 

Hmm. 

[rasa]

if you ever need a new battery and dont fancy doing it youself..then this is ptetty cheap...www.themasterlocksmith.com/product/bmw-key-repair/