Remote key locking won't work

[CybrSlydr]

How much was a new new key if you don't mind? I am in the same situation.

It was $250

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[Casa de Mesa]

An old battery in the key fob that's failing could do it.

[bmwfnatic]

Looks like this:

Don’t want to hijack this thread. But this has me wondering, my current M3 I need to be within about 10ft for the remote to work, I could’ve sworn with my previous one I could be 10 times further away and it would still work. What could that be?

[TropicalM3]

On the output side of the RF Antenna(the wires that lead to the GM5), there is a wire that will give a signal when you press a button on the key, I don't remember which one of the wires. My key wouldn't work for years until I tested that wire and found that a signal was going to the car, then I realised the issue was with the car, ended up being a blown fuse. Just use a test light, it will be a dull light bcse I think it is a 5v signal.

[sapote]

So, I've since replaced the broken pieces in the lock and fixed it. Key locks and unlocks the door and will also lock the passenger door. Key fob still a no-go.

Next idea is it's the RF antenna in the c-pillar or the gm5 module - any idea which one we think it might be more? I'm leaning towards the RF antenna. Is it underneath the sharkfin under the headliner?

Continue to use the key lock for lock/unlock will break it again. The lock design was intended to be controlled by the key fob.
I don't think your issue is the GM5, but the RF antenna wiring.

[Casa de Mesa]

Looks like this:

[01CB]

How much was a new new key if you don't mind? I am in the same situation.

[CybrSlydr]

So, I've since replaced the broken pieces in the lock and fixed it. Key locks and unlocks the door and will also lock the passenger door. Key fob still a no-go.

Next idea is it's the RF antenna in the c-pillar or the gm5 module - any idea which one we think it might be more? I'm leaning towards the RF antenna. Is it underneath the sharkfin under the headliner?

[sapote]

OP, if you know someone with working M3, then just program your key to their car (follow their working key) and see if its remote control buttons work or not. If it works then the issue is your wirings.

[sapote]

The key I used a long time ago stopped working. I assumed it was a dead battery, so I cut the key open and replaced the battery. It didn't work, so I just assumed it was my shoddy workmanship.

This helps to explain that I think the root cause is not about the keys, but the antenna amp wiring. This happened to my 323iT wagon once and I found the harness with 2 or 3 wires broken from many trunk openings. Don't know if the M3 have the same sort of cable harness that being moved/twisted when trunk opened.

[CybrSlydr]

Good news is they waived the diagnostic fee. So, I'm just out the price for the key.

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[heinzboehmer]

Antenna amplifier is really easy to get to. It's behind the driver's side c pillar. Good idea to check that all the connectors are seating correctly before doing other stuff.

I recently had my rear interior out and the screw ring thing for the radio am/fm antenna was undone, so it's possible that something isn't connected correctly.

[CybrSlydr]

I don't think it's GM5 issue as OP doesn't have problem of using the console central lock button. It's either the key was not programmed correctly or the RF Amp/wiring cable issue

They said it could be an antenna issue or a security system issue.

I did replace the door lock a few ueqrs ago because I had the issue with the key spinning in the lock in the door.

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[CybrSlydr]

, Understand that the new key doesn't , Do you have any old key that works? If not, what's the history of this problem?

The key I used a long time ago stopped working. I assumed it was a dead battery, so I cut the key open and replaced the battery. It didn't work, so I just assumed it was my shoddy workmanship.

Fast forward a few years to today and the key works in the physical tumblers, but they can't get it to work with the remote function.

I have another key, but am not sure if it's the valet key or second key.

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[CybrSlydr]

You may have to replace the latch module inside the drivers door. It’s pretty easy to do if you have small hands. There are plenty of YouTube vids on how. The dealership will want to charge an entire day of labor to do it. I was quoted over 2 grand. I was able to lock the doors with the button on the key but had to turn the key to unlock. Do the buttons inside lock and unlock the doors?

Yes, the console button does work tonlock/unlock the doors.

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