Key fob lock button works but doesn't...

tomrdy · Oct 5, 2018

I recently got around to fixing my "dead" second key - soldered in a new battery, and did the reset sequence. All is well and functional except locking.

Pressing the BMW roundel button does not lock the car. My first thought was the button or circuit for it is dead but realised that in order to successfully execute the reset sequence, that button had to have worked :| To my caveman eyes, the circuit board connections seem to look fine. Don't know about the chip looking things tho (ok I'm not qualified to make a judgement on the circuit board lol).

Thoughts? I'm thinking of getting the software to try and program in the window control functions for the key - I saw in a demo that there's a "key status" section? Could that reveal something?

joluga123 · Oct 26, 2018

Hi, I just registered when I saw your post.

I have exactly the same problem, I changed the battery and re-sync the remote. unlock and trunk works, locking does not. (keep reading).

Playing with the remote I found out something interesting. double click unlock and then lock immediately, as fast as you can. the car will lock.

My other keyfob is working fine, I think we have a defective remote.

dhobbs · Oct 27, 2018

I also have the same problem.
Got my spare key out to check it still works and the lock doesn’t work as you described.
I’ll try the double click method too.
Daz

fredej · Oct 29, 2018

One of my key suddenly stopped working for remote locking my car. All other function of the key was working. I tested with my spare key and that one was working normally.

In the BMW Technical Information System (https://www.newtis.info/tisv2/a/en/...locking-security-functions/remote-key/X7QRmgq) I found this:

Voltage monitoring

The charge level of the standard/rechargeable battery in the key fob transmitter when a button is pressed is monitored.

If the voltage drops to a lower limit, the key fob transmitter signals the battery condition to the basic module. The basic module processes that information as follows:

- The command "Lock vehicle" is not executed. All other functions are allowed.
-
The low voltage is registered on the basic module

The message is analysed by the diagnostic program for the radio remote control. It is automatically deleted once the voltage level on the key fob transmitter has been OK again 5 times in succession.

If low voltage occurs, the following operations are required:

- On key fob transmitters with standard battery, the battery must be replaced
- On key fob transmitters with rechargeable battery, the battery must be charged for at least 30 minutes in the ignition lock.
A non voltage-dependent memory in the key fob transmitter ensures that the initialisation data is not lost even if the battery is completely discharged.

When I get the chance, I will charge the key in the ignition and then do the unlock/open tailgate/turn on lights procedure 5 times and hope that the key will work normally after that.

fredej · Oct 30, 2018

I got the key to work!
I charged the key in the ignition for 1.5 hours.
After that I removed it, inserted it in the ignition again, turned it to position 1 and finally removed it again. This was repeated 5 times.

Then the lock button worked again.

tomrdy · Nov 1, 2018

joluga123 said:
Hi, I just registered when I saw your post.

I have exactly the same problem, I changed the battery and re-sync the remote. unlock and trunk works, locking does not. (keep reading).

Playing with the remote I found out something interesting. double click unlock and then lock immediately, as fast as you can. the car will lock.

My other keyfob is working fine, I think we have a defective remote.

Wow didn't realise this thread was responded to!

I just tried the double press method and it worked for me as well. I think you and I are in literally the same boat as far as our key issue is concerned!

fredej said:
got the key to work!
I charged the key in the ignition for 1.5 hours.
After that I removed it, inserted it in the ignition again, turned it to position 1 and finally removed it again. This was repeated 5 times.

Then the lock button worked again

Congrats! Did you do anything specific with the position 1 sequence? I ask because I've used my problem-key for weeks so would have put it into 1 many times (and it's still bummed). You mentioned something about lights and the trunk in your other reply?

The message is analysed by the diagnostic program for the radio remote control. It is automatically deleted once the voltage level on the key fob transmitter has been OK again 5 times in succession.

Im guessing that after replacing the battery, we haven't been able to get the module to OK the key status.

The PA Soft I was going to get has a "Key status" section in the software - my guess is there might be a way to OK the key from there... Guess I should head over to eBay!

fredej · Nov 1, 2018

tomrdy said:
Congrats! Did you do anything specific with the position 1 sequence? I ask because I've used my problem-key for weeks so would have put it into 1 many times (and it's still bummed). You mentioned something about lights and the trunk in your other reply?

I first tried to press different buttons on the key to get its status OK. That failed. So next thing I tried was to use the key in the ignition and turn it to position 1 several times. After that the lock button on the remote started to work.
I'm still unsure of what actions actually triggered the key status to OK.

tomrdy · Nov 17, 2018

Update: through PA soft I went through and looked through all the modules. Key status for my 2 keys are both enabled - I couldn't find anything related to key voltage level or any error relating to that I could clear.

Fun fact: there are 2 more keys out in the world that are supposedly enables for my car (lol).

I coded key remote control for the roof (which is awesome) but unfortunately the iffy key can't lock so it also can't close the roof. Opens the roof fine though.

This isnt a bit deal but getting quite frustrated now :headbang: :headbang:

Key fob lock button works but doesn't...

tomrdy

Member

joluga123

New member

dhobbs

Senior member

fredej

Member

fredej

Member

tomrdy

Member

fredej

Member

tomrdy

Member

Similar threads