Can't Sync Keys

[eskirvin]

I have a few key remotes, 4 China ones and 1 BMW key, that I can't get to sync. I've tried several different methods I've found throughout the forum. Something that's dawned on my recently though is that they all call for the doors to be closed. Using my IBUS app, I can see that my sunroof is considered open as it is highlighted in orange. Could that prevent me from syncing my keys?

[StephenVA]

I am sure you found many instructions sequences posted many many years ago that could be relevant today. I will re-post these proven to work instructions as the original poster has long since left the community for some other brand, as there are others who are getting their X5 for the first time as the 4th or 5th owners.

Key Programming Instructions

Remember...you will need to have BOTH remote keys with you when you program the new key. Any remote key NOT reinitialized during the same session will NOT communicate with the GM...and will not lock/unlock & arm/disarm the car using the remote buttons.

Each programming session assigns a specific key code and new rolling code table to the keys...so any remote key NOT present will not have the update...thus will not work remotely.

Here's the programming instructions just in case you need them...plus some tips that some fail to follow...thus fail to initialize their remotes:
KL R = ignition position 1 (1st click after the OFF position...not position 2 or with engine running)
All doors must be closed
All doors must be unlocked
Only insert the 1st key into the ignition...after STEP 6...start programming the 2nd remote on STEP 3 where you start pressing the buttons
Remember...you will need to have BOTH remote keys with you when you program the new key. Any remote key NOT reinitialized during the same session will NOT communicate with the GM...and will not lock/unlock & arm/disarm the car using the remote buttons.

Each programming session assigns a specific key code and new rolling code table to the keys...so any remote key NOT present will not have the update...thus will not work remotely.

Here's the programming instructions just in case you need them...plus some tips that some fail to follow...thus fail to initialize their remotes:
KL R = ignition position 1 (1st click after the OFF position...not position 2 or with engine running)
All doors must be closed
All doors must be unlocked
Only insert the 1st key into the ignition...after STEP 6...start programming the 2nd remote on STEP 3 where you start pressing the buttons.

Good luck!

[andrewwynn]

Originally Posted by eskirvin

I have a few key remotes, 4 China ones and 1 BMW key, that I can't get to sync. I've tried several different methods I've found throughout the forum. Something that's dawned on my recently though is that they all call for the doors to be closed. Using my IBUS app, I can see that my sunroof is considered open as it is highlighted in orange. Could that prevent me from syncing my keys?

Yep. I think all doors and windows need to be closed. Also the lock status of the doors so have to be the same. Locked or unlocked but I never remember which. Does your alarm set when you lock the door?

[eskirvin]

Originally Posted by andrewwynn

Yep. I think all doors and windows need to be closed. Also the lock status of the doors so have to be the same. Locked or unlocked but I never remember which. Does your alarm set when you lock the door?

I didn't know I had an alarm. Does all doors and windows include the sunroof, which I guess is technically both?

[white46]

Also make sure you've purchased correct MHz key.

[eskirvin]

Originally Posted by white46

Also make sure you've purchased correct MHz key.

Yes, I learned that lesson. I have 4 China keys that supposedly switch frequencies with a button combination, but I have no way to verify. My X5s use 433 MHz. The BMW key is the same old one that used to work, but the battery died. I replaced the battery, but it doesn't work anymore. I also recently replaced the GM3 to solve some door locking issues.

[andrewwynn]

More often than not the " battery died " is actually just cold solder joints . I've done Reflow on a couple keys to make them work again otherwise the buttons also will break and that will cause malfunction. If you can open up the key check the voltage. Also did you replace the battery with an appropriate 3 volt rechargeable lithium battery


Sent from my iPhone using Tapatalk Pro

[upallnight]

Most people who never replaced a battery in a BMW FOB don't know how to do it correctly and end up damaging the circuit board on the FOB. You wouldn't do brain surgery on your spouse what makes you think you can open up a seal fob and replace the battery.

[oldskewel]

Here's a thread with possibly related info from Qsilver7:
https://www.bimmerfest.com/threads/k.../#post-8140995

Here's one for when I did surgery on a couple of my BMW key fobs (genuine BMW, bought used off eBay and reprogrammed for keyless entry but not EWS):
https://xoutpost.com/bmw-sav-forums/...r-options.html

But to answer your first, direct question, I'll suggest (not knowing for sure) that yes, since your system thinks your sunroof is open when it's not, that will affect the whole keyless entry system including preventing successful reprogramming.

Do you have other system locking control problems?

I once had a flaky driver's door lock actuator (DLA). It kind of worked, but (from memory):
- sometimes unlocking would appear weak, rear doors might only unlock half way, etc.
- the central locking/unlocking button on the center console did not work at all
- remote entry had been flaky, and then when I tried to reprogram them all, it was very reliably not working at all. And I've reprogrammed several times over the years, generally with no problems.

After I finally got BOTH my foxwell and my PASoft BMW Scanner doing serious debugging, I found that the system thought that the driver's door was open, even when it was closed.

Jumping ahead to the answer, this single fault was the root cause of everything not working. Perhaps a simple problem with the microswitch door latch position detector. I swapped my mechanically compromised but electrically good driver's DLA assembly back in there, and everything instantly was perfect again. So then I fixed it mechanically and am still running with it.

Rear door locking / unlocking, which had appeared weak doing Foxwell active testing, was solid and strong. Key programming worked again, etc. BTW, I probably have a thread on here about that whole episode with more accurate details vs. my memory here.

So I will guess that the sunroof thing is the problem. Especially if the sunroof is actually closed when it says it's open.

It's not clear whether the sunroof would count as a "door" with regard to the rules for programming. But if it says it's open when it's closed, it indicates a problem in this very complex system, and things could shut down anyway.

The fact that you did not know you have an alarm suggests even more that there is a system problem. Does the "clown nose" red knob / light under the rearview mirror flash when the car is locked?

Also, speaking from painful experience, having a failed keyless entry will make you rely on the driver's door key lock for entry. And that thing is not designed to be used regularly. It will break within less than a thousand uses, I think. And then you'd need to figure out how to break into the car without damaging anything. And the "secret" method for doing that relies on a functioning central locking system, so you'd be stuck like I was.

And regarding your battery-replaced BMW fob, I'd not give up on that yet. The way the system works, it should appear completely dead if there is a problem as I'm suggesting here. Get that fixed, and the fob may then program and work just fine.

[crystalworks]

Originally Posted by andrewwynn

More often than not the " battery died " is actually just cold solder joints . I've done Reflow on a couple keys to make them work again otherwise the buttons also will break and that will cause malfunction. If you can open up the key check the voltage. Also did you replace the battery with an appropriate 3 volt rechargeable lithium battery

Yep, almost every non-func FOB I've opened had a broken battery solder joint from years of being dropped and handled... well, like a key.

Not sure the brain surgery analogy holds up... but yes, if you are completely ham-fisted or very impatient, don't attempt to replace one of these batteries.