Advice required - central locking problem

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bugsy
Joined: Wed 01 Apr, 2009 10:12
Posts: 47

  M roadster S50
Location: Sutton

Advice required - central locking problem

Post by bugsy » Thu 14 Apr, 2016 13:07

Hi,

I have a problem with the central locking that has developed over winter. Just want to check if people think it's the passenger door actuator that is the cause.

Problem is the key remote signal won't unlock the car. The interior light goes on (suggesting receiving a signal). The key remote signal will lock the car.
Unlocking at the boot or driver's side door unlocks that lock only. Opening the door set's off the alarm.
Disconnecting and reconnecting the battery usually unlocks all doors, but the alarm goes off upon opening the drivers side door.

The only way currently to drive the car is to disconnect the battery, open the doors (usually the passenger door will open, sometimes not), connect the battery and then I can start the car without the alarm going off. But sometimes this takes a few attempts. I may have to lock the car from the key remote signal (with the boot open) before disconnecting the battery.

I cannot see any problems with wiring in the boot. My battery was replaced last year and is fully charged. I would assume if there was a fuse problem the entire central locking wouldn't work.

From the web searching and articles below, I believe it is the actuator that's the problem and I need to buy & fit a new one.

Does anyone disagree? Should there be something else I should look at beforehand?

Cheers
Pete

Found this previoulsy mentioned. Haven't tried this yet but I don't expect it will work for me:
This has happened to me twice now on the passenger door. To fix it i have to set of the alarm by lowering the hood arming the car then after 30 sec lean in the car and set of the alarm !!! dont ask me why but each time the door lock works again. May be worth a try.

Articles I've found researching:
http://www.zroadster.net/forum/viewtopic.php?t=17528
http://www.pelicanparts.com/BMW/techart ... ain_Z3.htm
http://cgi.ebay.co.uk/Door-Locking-Actu ... 240%3A1318

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Robert T
Site Admin
Joined: Mon 12 Jun, 2006 11:35
Posts: 9984

  Z3 roadster 1.9
Location: Cheshire

Re: Advice required - central locking problem

Post by Robert T » Thu 14 Apr, 2016 18:55

My guess would be a break in the lock wire somewhere, possibly the boot loom. You need to do some more testing to determine where the fault lies. What happens when you unlock from the boot for example? This should operate the central locking. Similarly, if you press the button on the drivers door down whilst in the car, then pull the door handle, it should release the central locking on both doors.

Which alarm do you have? The one with the separate fob or the one with the buttons on the key? There are different disarming procedures for each.

Cheers R.

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Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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DC
Joined: Tue 15 Sep, 2009 18:31
Posts: 559

  Z3 roadster 1.9
Location: Inverness-shire

Re: Advice required - central locking problem

Post by DC » Fri 15 Apr, 2016 09:51

I had some weird central locking issues a couple of years back which I found was due to the boot loom (where it goes from lid to body) as Robert suggests.
It looked perfect but on stripping the outer cover back there were a couple of broken wires.
Dave.
Dave. 1998 Arctic Silver Z3 M44 1.9 Automatic

bugsy
Joined: Wed 01 Apr, 2009 10:12
Posts: 47

  M roadster S50
Location: Sutton

Re: Advice required - central locking problem

Post by bugsy » Fri 15 Apr, 2016 13:33

I found was due to the boot loom (where it goes from lid to body)
Thanks DC. I thought that I had done a close check but I will recheck this weekend.

What happens when you unlock from the boot for example?
Thanks Rob. It only open the boot

Similarly, if you press the button on the drivers door down whilst in the car
It only locks the drivers side door. I forgot to mention that prior this problem, I was having an intermitant problem that the car kept unlocking itself approximately 20 seconds after locking.

Which alarm do you have? The one with the separate fob or the one with the buttons on the key?
Buttons on the fob.

Lewy
Joined: Mon 22 Oct, 2012 18:34
Posts: 203

  Z3 roadster 2.8
Location: Wolverhampton

Re: Advice required - central locking problem

Post by Lewy » Fri 15 Apr, 2016 20:10

Before going to great expense have you changed the keyfob battery?

I had an issue recently where the signal was strong enough to unlock the car but wasn't strong enough to disarm the alarm so every time I opened up, sirens a plenty!

Since changing the key fob battery for the grand sum of £1.20 I haven't had a problem.

Certainly a starting point if you haven't tried this yet. :)

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Bin
Joined: Sat 12 Mar, 2016 20:50
Posts: 41

  Z3 roadster 2.2i

Re: Advice required - central locking problem

Post by Bin » Sat 16 Apr, 2016 11:07

Check the two torx screws that hold the boot lock assembly in place haven't come loose, allowing it to move freely as this will trigger the central locking mechanism and might thus interfere with it. Seems unlikely, I have to say, but worth a look.

bugsy
Joined: Wed 01 Apr, 2009 10:12
Posts: 47

  M roadster S50
Location: Sutton

Re: Advice required - central locking problem

Post by bugsy » Tue 19 Apr, 2016 11:55

It was a tale of two days. On Saturday I got out the spare fob, reconnected the car battery and everything worked ok. For the rest of the day.
But on Sunday, the central locking stopped working after a few minutes. Obviously it was observing the day of rest.

I didn't get time to check all the things suggested because I was cleaning the headlights, but will hopefully have time this evening.
@Ben - thanks for that suggestion. Will look at the bolts.

bugsy
Joined: Wed 01 Apr, 2009 10:12
Posts: 47

  M roadster S50
Location: Sutton

Re: Advice required - central locking problem

Post by bugsy » Mon 04 Jul, 2016 12:08

I thought that I'd give an update in case it helps anyone else. After checking all wires, fuses and bolts and even buying a new actuator, I finally worked out what was causing the problem.

The central locking problem started at the time of having a flat battery which I replaced at the beginning of the year. I was leaving the battery disconnected while I had this locking problem. Through various tests I found that if I change the locking state after disconnecting the battery (e.g. unlocking the drivers door) I was getting the problem. But if I connected the battery with the locks in the same state when the battery was disconnected, I didn't get the problem.

It would suggest that the locking electrics kept an internal state and if restoring power with the doors not in their previous state, it got confused and wouldn't allow unlocking.

Now I have understood this rules, I haven't got a problem. Central locking continues to work perfectly since.
This may not be true for the rest of you, but each car has it's "mannerisms" - this seems to be mine.

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