SOS Z3 ALARM CENTRAL LOCKING ISSUE

[jennals]

Hi all,

I’m having a strange alarm/central locking issue on my 1998 BMW Z3 2.8 and I’m hoping someone has seen this before.

Originally the issue started with the alarm going off every time I unlocked the car and opened a door. The central locking would work, but as soon as any door opened the alarm would trigger. The electronic key has never worked since owning the car so I only can use my physical key.

I then found a broken white 12V wire in the boot lid loom where it bends near the hinge. I repaired/soldered that wire and replaced a blown Fuse 33.

Since repairing it:

- The boot lock now works correctly again with the central locking, physical key.

However, I still have the following issue:

When I unlock the car and open ANY door or the boot:

- the hazards flash
- and the alarm sounds

If I leave the doors shut after unlocking, the alarm will stop after about 30 seconds. If a door stays open, the alarm continues.

Current fault codes from the ZKE module are:

- Central locking drive, driver’s door open circuit
- Central locking open circuit
- Central locking rear lid open circuit
- Line Terminal R missing

Additional notes:

- Radio/windows/accessories all work normally with ignition on
- Boot loom has been visually inspected and I can’t currently see any other broken wires
- Voltage at the battery is healthy 13.1v
- The issue changed after repairing the boot loom wire and replacing the fuse
- I have replaced the bonnet sensor
- Rear left tilt sensor/ module is not under water and appears fine
- I also tried unlocking the car, reaching through the open window, and turning the ignition on before opening a door — the alarm still triggered.

At this point I’m wondering:

- hidden loom break?
- bad ground/shared signal wire?
- driver door lock actuator/microswitch?
- ZKE module fault?

Has anyone had similar symptoms or know where I should focus next?

Thanks!

 

[Gatsoburner]

Similarly I had a central locking issue, on closing the boot at home fortunately...the car locked itself. I was gobsmacked.
Spare key obtained and unlocked it.
Issue was as you say, loom at the boot lid NS was goosed, around 5 of the cables either snapped or well the way to it.
Repaired all and all was fine. Just recently though the alarm spuriously triggers. WD the tilt module in the NS lower arch behind the carpet, where roof motor is, and fingers crossed it's ok.
If I was you, recheck your repairs, check on the alarm tilt sensor

 

[Althulas]

Hi and welcome. Do you have the tombstone type key or the separate alarm fob? From reading your description I interpreted that you are not using anything to disable the alarm system.

 

[jennals]

Similarly I had a central locking issue, on closing the boot at home fortunately...the car locked itself. I was gobsmacked.
Spare key obtained and unlocked it.
Issue was as you say, loom at the boot lid NS was goosed, around 5 of the cables either snapped or well the way to it.
Repaired all and all was fine. Just recently though the alarm spuriously triggers. WD the tilt module in the NS lower arch behind the carpet, where roof motor is, and fingers crossed it's ok.
If I was you, recheck your repairs, check on the alarm tilt sensor

Thanks alot for the advice. I will check this further.

 

[jennals]

Hi and welcome. Do you have the tombstone type key or the separate alarm fob? From reading your description I interpreted that you are not using anything to disable the alarm system.

Hi thank you for the message. I just have the x1 tombstone key that doesnt have a fob. Ive taken it to my local key man and he can see its transmitting a signal fine. Ive taken the glove box out and been on reset button but cant get it to sync so like you mentioned i cant disengage the alarm. Even putting the key in the ignition doesnt stop the alarm only turning the engine on does.

 

[Althulas]

Have you tried any of the following in this thread posts 1 and 9.

Programming your BMW Z3 key fob

Just changed the batteries in both my key fobs using this process and it worked first time on both fobs. This is only relevant to this style key as far as I know. May work for the diamond key version I'd guess. Instructions found on an E46 forum. Key into the ignition and turn it to the...

zroadster.org

 

[jennals]

Have you tried any of the following in this thread posts 1 and 9

Have you tried any of the following in this thread posts 1 and 9.

Programming your BMW Z3 key fob

Just changed the batteries in both my key fobs using this process and it worked first time on both fobs. This is only relevant to this style key as far as I know. May work for the diamond key version I'd guess. Instructions found on an E46 forum. Key into the ignition and turn it to the...

zroadster.org

Programming your BMW Z3 key fob

Just changed the batteries in both my key fobs using this process and it worked first time on both fobs. This is only relevant to this style key as far as I know. May work for the diamond key version I'd guess. Instructions found on an E46 forum. Key into the ignition and turn it to the...

zroadster.org

Morning, thanks yes I have tried this process and a few others countless times with no joy. I should mention that this was triggered when my battery died. I charged it up and since then when I reconnected the ground its been doing this with the alarm/ doors.

Previously the alarm never worked, went off or even the LED red light on the console area never turned on. I brought my Z3 a few years ago and im sure he told me thr alarm was deactivated.

 

[jonco]

Taking account of the many comments, I would recheck the `loom of doom' i.e. boot lid hinge wiring which can throw up all sorts of strange problems.
You have found one broken wire but there may be others. You can do this easily by exposing cable cores in boot lid and physically pulling one at a time. When I did mine I pulled through an additional 2 broken wires which looked ok externally. Good Luck.

 

[jennals]

Taking account of the many comments, I would recheck the `loom of doom' i.e. boot lid hinge wiring which can throw up all sorts of strange problems.
You have found one broken wire but there may be others. You can do this easily by exposing cable cores in boot lid and physically pulling one at a time. When I did mine I pulled through an additional 2 broken wires which looked ok externally. Good Luck.

Hi, thanks for this. Because of it I have been fully investigating the loom in depth. I cant see anything wrong with any other wire though. Ive exposed and pulled both ways like you mentioned one at a time and they're all good. No movement. Ive also checked every single fuse and all good. When I had the bonnet open though, the alarm was automatically going off again regularly I wondered if it eas because I touched the wires that go into the bonnet sensor I replaced but I couldn't be sure.

 

[jennals]

Similarly I had a central locking issue, on closing the boot at home fortunately...the car locked itself. I was gobsmacked.
Spare key obtained and unlocked it.
Issue was as you say, loom at the boot lid NS was goosed, around 5 of the cables either snapped or well the way to it.
Repaired all and all was fine. Just recently though the alarm spuriously triggers. WD the tilt module in the NS lower arch behind the carpet, where roof motor is, and fingers crossed it's ok.
If I was you, recheck your repairs, check on the alarm tilt sensor

Hi ive now checked all the wires in the loom and it's all good.

I dont seem to have a tilt sensor though? As per many YouTube videos it seems to be in the lower NS boot well, but theres nothing there? Behind the motor there is a couple of small purple modules but thays all I can see. All wires around there appear to be attached and good.

 

[Althulas]

It still sounds like a communication fault of your can’t get your key to sync with the alarm module. I know you said that someone said your key was ok but this might be worth a cheap punt https://ebay.us/m/QTowUq if it works you can transplant the circuit board into your key case. Or send your key off to one of these https://ebay.us/m/aasqH4 to make sure that your key is fully functioning.

 

[jennals]

It still sounds like a communication fault of your can’t get your key to sync with the alarm module. I know you said that someone said your key was ok but this might be worth a cheap punt https://ebay.us/m/QTowUq if it works you can transplant the circuit board into your key case. Or send your key off to one of these https://ebay.us/m/aasqH4 to make sure that your key is fully functioning.

Strong shout - thank you. I've just ordered one. Ill keep you updated.

 

[Althulas]

I hoped you looked at it carefully to make sure you’ve ordered the correct one

I sure you looked at a few vids but just in case

View: https://youtu.be/P3MFtfYgHfI?si=Zyode-LuPEnU_1qi

 

[jonco]

Tilt sensor was an optional extra - My '98 doesn't have one. you have mentioned bonnet switch - you can actually un-plug this and rest of system should still work - been there done it

 

[Althulas]

Funny how there seems different ways to sync the tombstone type keys

View: https://youtu.be/o9LWhnewgNM?si=FfWZ34OVFRTLcnP6

 

[jennals]

I hoped you looked at it carefully to make sure you’ve ordered the correct one

I sure you looked at a few vids but just in case

View: https://youtu.be/P3MFtfYgHfI?si=Zyode-LuPEnU_1qi

Yeah Ive ordered one to match my current key. Ive gone gone for this one: https://ebay.us/m/RBvwSk

You are also right theres a few ways to sync these keys including this video which gets into the glove box and moves a toggle switch button:

View: https://youtu.be/rShtmVkI3gw?si=WBkKxi0VJmgHbUWx

 

[jennals]

Tilt sensor was an optional extra - My '98 doesn't have one. you have mentioned bonnet switch - you can actually un-plug this and rest of system should still work - been there done it

Theres no error code on the diagnostic that a tilt sensor is the drama either unlike this video (18 Sec) :

View: https://youtu.be/9Y7eEsHvFcg?si=1_pZy_C3DH2184X2


But the fact you mentioned they were an optional extra makes sense, as I was going to rip it apart tomorrow to find it.

 

[jennals]

Hello all, some progress has finally been made!

I’ve taken apart the dash and removed the alarm module. I unplugged all the connectors and plugged them back in, and now the hazards no longer go off every time I touch a door!

Now I’m trying to get the electric key/fob working. The key I originally had has never synced with the car. Since I now have the alarm module out, I’ve been able to put it into pairing/learn mode, but still no luck.

Following advice above, I bought a matching key from eBay, but that won’t sync either. I’ve tried the usual syncing methods:

- ignition on/off procedure
- holding unlock while pressing lock 3 times
- holding lock while the alarm module is in learn mode

Still nothing.

My question is: all the YouTube videos for this alarm module seem to show the older “brick” style fob. Does this mean I’ve actually had the wrong key/fob for my Z3 all along?

Any advice would be much appreciated!

 

[jonco]

.............My question is: all the YouTube videos for this alarm module seem to show the older “brick” style fob. Does this mean I’ve actually had the wrong key/fob for my Z3 all along?.........

It's some years since I looked into it and the memory fades, but you may well have had wrong fob.
Unfortunately our cars were built in the change-over period from alarms which were dealer installed to factory fit. Dealers were using stock up off their shelves. Mine is Dec `97 build and alarm was dealer installed. I also helped another member re-programme his spare fob on a `99 model- both were `house brick' fobs but the module boxes were slightly different.
Some photos in this, where you can see part numbers for comparison. https://zroadster.org/threads/3g-ews-remote-fob-programming.3384/
I fixed mine a number of times and programmed different fobs over the years, but in the end the system gave up and I removed it. Just use the key now.

 

[jennals]

It's some years since I looked into it and the memory fades, but you may well have had wrong fob.
Unfortunately our cars were built in the change-over period from alarms which were dealer installed to factory fit. Dealers were using stock up off their shelves. Mine is Dec `97 build and alarm was dealer installed. I also helped another member re-programme his spare fob on a `99 model- both were `house brick' fobs but the module boxes were slightly different.
Some photos in this, where you can see part numbers for comparison. https://zroadster.org/threads/3g-ews-remote-fob-programming.3384/
I fixed mine a number of times and programmed different fobs over the years, but in the end the system gave up and I removed it. Just use the key now.

Thanks, Jonco — that all makes sense.

When you mentioned you'd programmed a few remotes, have you ever successfully programmed a 3-button remote like mine using the alarm module's learn function, or was it always the older brick-style remote that you managed to sync?

I've gone ahead and ordered a £50 brick remote from eBay, so fingers crossed that does the trick. If not, I'll probably replace the alarm module and see if that solves it. At this point, I'm determined to get the remote locking working!

What has me stumped is the possibility that my 3-button key is simply the wrong one. The key itself looks well used, so I wonder if a previous owner replaced it years ago and just chose the newer-looking key without realising the remote and alarm module still need to be compatible and sync correctly.