[redoxsrb]

Hi everyone,

First off, I want to apologize if a post has already been made on this topic. I searched for a solution but was unable to find it.

I've had my BMW E92 LCI (2011) since April this year and never had any major issues, especially relating to electronics.

Around mid September I had an issue with the unlocking, the car became unresponsive to the key and wouldn't unlock. I tried the mechanical key, but it wouldn't turn so I couldn't unlock it. Luckily, after a few minutes and a couple of attempts it unlocked and started without any issues.

About a week later, I drove the car without experiencing the issue again, but then it happened, although this time I couldn't unlock it after 15 minutes and decided to walk home and try again tomorrow. Coming back the next day, I managed to unlock the car and drove down to a local locksmith who checked the battery on the key and it was fine.

I went searching for a replacement mechanical lock/key and was having trouble finding the parts I needed, and in the meantime it happened again, but this time it lasted for two and a half days. I decided to get a locksmith over who opened the car using the airbag to make room through the passenger window and a wire to open via the inside handle. He tried picking the lock for over an hour and a half, but couldn't as pin 6 was stuck (which is why I couldn't open it with the key. Opening the car this way had the alarm go off, but as soon as we put in the key it stopped and the car started right up.

I managed to find a replacement mechanical lock and key and, as my 12v battery was quite old I decided to replace it. Having changed the battery I haven't had any issues until this past Saturday.

The same issue occurred, although this time I had the mechanical key as a backup. I popped the door open, however, this time the alarm didn't activate. I inserted the key, and the car wouldn't start. I couldn't open the trunk as it doesn't have a physical lock to check the battery, but managed to unlock the car again while walking around and spamming the unlock button. The car started right up without any struggling.

I'm honestly at a loss and need your help, my knowledge is minimal, but connecting the dots (alarm not going off and the car not having power with the key inserted) I'm under the assumption that the car loses electrical power randomly, causing the CAS(hope I'm not wrong) not to have power and being unable to communicate with the key, the alarm light not blinking, and, obviously, not having power to start.

What's mind boggling is that I don't have to do anything/can't do anything to get the power back, and it happens randomly just through waiting. Every locksmith or electrician I called either said they don't operate on such things, never had similar cases, and/or requiring a visit that ends up with me paying for their services without a solution or even a diagnosis.

I am stuck and losing my mind every time I have to drive somewhere wondering if today it, again, won't unlock or start. The worst thing is that I can't replicate the issue to have it properly diagnosed, which means I have to wait for it to happen, just to call someone to diagnose, and have it "fix itself" by the time they arrive.

I tried supplying power through the leads under the hood and it did nothing. I can't access the boot as I have no keyhole, no ski hole, and the seat fold down release can only be accessed from the trunk.

To get ahead of some questions people I spoke to already asked to avoid your time being wasted:

1. Is it a CA equipped car? No, I have the base key with the battery that's soldered on the PCB.
2. Do I have 2 keys? No, I only have the one and new keys are expensive where I'm from (ranging between 120€ and 200€, where as a replacement CAS for example is 50€).
3. Is the alternator working? Yes, I had it tested while replacing the battery, it's charging well. Although I do have some belt squeaks which I'm going to have replaced on the 4th once the parts arive.
4. Do you have any errors? No, not on the board computer, or via OBD2 diagnostics.
5. Have you checked the fuses and relays? Yes, I've checked every fuse and relay related to locking/unlocking or electrical components.

I would really appreciate some help or input from someone more knowledgeable or experienced on the topic as I'm at a dead end and don't want to sink hundreds of euros on parts replacing them and waiting weeks/months to know if the replacement I made changed anything.

Thank you in advance and I apologize if I made any mistakes while creating this post, any grammatical errors (point and laugh), and for the length of the post.

TL DR Experiencing a potential intermittent electrical loss, being unable to unlock or start the car with a new battery and functioning alternator. No spare key, checked diagnostics, unable to replicate issue, lasting anywhere between 5 minutes and 2 days, with no issues present after fixing itself.

[ctuna]

I would take this to the main board as this is the audio board.
Also you may fine there is little feedback on the 320 here because it
is a Euro model and most of the member here are in the US where we never had the 4 cylinders .

There was a recall for the Electrical Connector to the Main Cabin Fuse board here in some years.
(Power Connector)

Always be sure you have a strong battery and alternator before going further in trying to diagnose problems on these.