Alarm Activates When LOCKING Doors after short at Trunk Lock actuator

[Jehu]

I caused a short when I made a connection from one of the two power wires for the trunk actuator to one of the command/signal lower voltage wires from the other connector.

Now the alarm goes off when locking the doors.

I think I made it worse in fumbling desperation by disconnecting what I think is the Trunk mounted level sensor (tow away sensor) and at this time the remote (three button Fob) no longer communicates with the car even after re-connecting this sensor.. maybe an initialization block?

Anyway.. I had the car scanned by a BMW trained tech who knows e34 540's he used to do the short block swaps way back.

He suggested I may have damaged an actuator .
The locks lock then open then lock again as the alarm is triggered.


There was no initialization block when he scanned it.

I was unaware an actuator could be damaged in a way that would cause it to trigger the alarm . I thought their failure just caused the system to kick back and you have to re-lock.

Just wanted to see if anyone had a brainstorm with this.. I have a copy of the BMW EWS but haven't looked at it much as reading schematics is a skill I have yet to grasp.

I am assuming the shorting which occurred would need to be traced to the next nearest component first which could in any way trigger the alarm.


anyway I hear or heard before disconnecting that trunk mounted level sensor the clicking in both the back seat locking unit and the front left A pillar/foot well mounted Alarm module..

I am willing to replace actuators and whatever modules may have been damaged yet I am hoping I might proceed with better understanding which could help avoid unnecessary expenses

Its been a rough few weeks here.. Hope everyone is doing well.

[whiskychaser]

As I understand it, the GM senses the position of the locks via the switches on the actuator. So if the boot lock actuator is damaged, that may be causing the problem. Not sure about your car but I think the part number on mine is 8353000. May be worth swapping one from a breakers and checking what signals the GM is getting from it.

[Jehu]

As I understand it, the GM senses the position of the locks via the switches on the actuator. So if the boot lock actuator is damaged, that may be causing the problem. Not sure about your car but I think the part number on mine is 8353000. May be worth swapping one from a breakers and checking what signals the GM is getting from it.

While the Trunk Lock Actuator was disconnected completely when I did this and the doors did lock properly via the remote key before the shorting which to me rules out a faulty Trunk Actuator (remember it did lock my doors precipitating this bother) I gather if your logic is accurate damage was done to a door actuator .

So you're sure the method by which the Alarm System receives door locking condition is triggered within the actuator?
8469

[whiskychaser]

Well, you can't have shorted out the boot actuator if it wasn't fitted :-) But this is how I understand central locking works: The boot and front door switches send open/close signals the GM. The GM then signals the relay module which powers up the motors to open/lock the doors. The GM monitors actuator switch positions so it knows if the boot lid or a door is open or closed. The alarm module monitors the central locking and AFIK, you can't set the alarm without the car being double locked. That may sound like so much gibberish but if you check out section 10 in the file below, you will see what I mean. It is in German but includes diagrams for the GM and switches:
http://twrite.org/shogunnew/files/EDC%20-%20Central%20Chassis%20Electronics.pdf

[Jehu]

Well, you can't have shorted out the boot actuator if it wasn't fitted :-) But this is how I understand central locking works: The boot and front door switches send open/close signals the GM. The GM then signals the relay module which powers up the motors to open/lock the doors. The GM monitors actuator switch positions so it knows if the boot lid or a door is open or closed. The alarm module monitors the central locking and AFIK, you can't set the alarm without the car being double locked. That may sound like so much gibberish but if you check out section 10 in the file below, you will see what I mean. It is in German but includes diagrams for the GM and switches:
http://twrite.org/shogunnew/files/EDC%20-%20Central%20Chassis%20Electronics.pdf


Ok the locks do double lock if I lock either of the front doors with either the door button or key blade in the tumbler.

For now I'll ignore the remote system . It was working until I unplugged that leveling sensor so I am assuming that caused a block to the remote but it was functioning fine right along .

Is it logical to look at one of the door actuators now due to receiving a 12V surge from my jumpering and is now letting a signal through to the alarm when entering the LOCKED position?

Without yet properly understanding the circuitry of these door actuators that seems to make some sense.

I am guessing the very nearest component to the wire I jumpered would be the first one to replace.

Well I'll grab a couple of cheap-o chinese actuators off ebay and see where that gets me beyond $50 poorer..

I very much appreciate your taking some time to help em think this through.

All the BMW indy shops round here are booked for weeks and the one I did have scan the car found nothing clearly at fault

[whiskychaser]

I'd hang fire with buying anything. Getting to the front door actuators would be a right PITA and if both doors double lock and unlock, it may be a fruitless exercise. My concern would be possible damage to the GM. I know it has a power protection relay but I don't think it is intended for this kind of problem :-) I think you mentioned it is a 540i but maybe confirm build year/month? If you are in the US, you may have the Alpine system but perhaps confirm that too? That way we will all be looking at the same diagrams :-)

[Jehu]

Not an Alpine system build is 1/95.

I ordered for $20 a rear actuator thinking this could be nearest the trunk in series and I seem to recall once or twice while trying to get an idea what was going on that one of the rear doors was not locking along;

I have another 540 accessible so maybe I'll grab the GM and RM from that and see if it works..

I am sort of still thinking about the DWA module and reading this part requires the dealership reprogramming under certain circumstances

I may bring that along from my other 540 too and then with all these items new I can see about having the dealer or someone with the necessary software to zap the unit to re connect with the key.

As for the door panels. I have replaced an actuator in the front passenger door before and the day before I screwed up I replaced the driver's door brake so had that panel off.

Its not always as bad doing the job as it is contemplating it. Especially when here my alternative is not being able to easily lock the car.

I use it to transport expensive IV drugs for a pharmacy so it could get really annoying if I find I need to lock the car with boxes of stuff in the back seat and need to disconnect the battery ..

[whiskychaser]

My apologies. I missed that you have got your model details on the footer :-)

I don't know which DWA module you have but AFIK 8355139 is the alarm and ultrasonic control module. It also controls the horn and has an external fuse. Not sure if the horn would function if that fuse were blown but it might be worth a look

[Jehu]

My apologies. I missed that you have got your model details on the footer :-) I don't know which DWA module you have but AFIK 8355139 is the alarm and ultrasonic control module. It also controls the horn and has an external fuse. Not sure if the horn would function if that fuse were blown but it might be worth a look the horn will be silent if I pull the fuse on this unit but the lights still flash and since losing communication between the remote and the car as I mentioned they flash for the full several minutes.. so I just don't bother since pulling the fuse loses me the OBC function.

[whiskychaser]

That's the one :-) As you say, it contains the horn relay and powers the OBC. If it is DWA4 I think you can only disarm the alarm with the remote. Have you tried to turn it off using the emergency procedure or resync the key? You don't need to code the module for either of those

[Jehu]

That's the one :-) As you say, it contains the horn relay and powers the OBC. If it is DWA4 I think you can only disarm the alarm with the remote. Have you tried to turn it off using the emergency procedure or resync the key? You don't need to code the module for either of those


before losing COM between the key and car I did both the normal key initialization ( pos 1 hold button 2 while pressing button 1 three times and the system DID respond normally as far as the locks but the alarm was triggered. Same when I tried resync starting with key in passenger door lock. alarm gets triggers however the doors get locked.

My thought about the unit I pictured is that the dealership or someone with the necessary software needs to reprogram it for the key or I think this is what I've read.

So if I head up to get this along with the GM and RM from my other 540 it may need to have some reprogramming to work with the remote although if any of them are damaged by my shorting the alarm issue may be resolved.

The only snag if perchance all else would be a solution is the other 540 is a NON EWSII while this car is EWSII so it may be there is some feature on the GM or RM which could be incompatible with this car HOWEVER I do have a DMW with the EWS pin cut and I have that in the car at this time. Not sure if I would need to replace the original DME when having the DWA unit reprogrammed with the key

[whiskychaser]

The info I have is you hold button 1 and press button 3. That will be the left hand button of the two. But I am sure you know your car a lot better than I do :-) I'm not a great lover of substitution as it may just introduce more unknowns. But I realise you don't have time to ponder. Do you have the LED which tells you the state of the alarm?

[Jehu]

The info I have is you hold button 1 and press button 3. That will be the left hand button of the two. But I am sure you know your car a lot better than I do :-) I'm not a great lover of substitution as it may just introduce more unknowns. But I realise you don't have time to ponder. Do you have the LED which tells you the state of the alarm?

Yes on the dash vent.. when I set it off it blinks... Stays that way till I yank the battery cable off

yah I may have misidentified the button numbers but I have done it correctly many times whatever their correct assignation is.

I also grabbed the GM,RM and DWA unit from me other 540..

The GM which came with this 540 has a series of numbers following and in addition to the part numbers on the GM from the older , earlier build 540... regardless I disconnected the neg batter cable and swapped in just the RM and GM with no changes in this problem ..

I was just too annoyed to bother with the DWA module . It requires some acrobatics to remove and my back is utterly wrecked but I also grabbed the rear-view mirror .

I never learned how the rear-view mirror operates in the remote locking system but since there was no change I assume its entirely passive in that there is no stored information its just a transmitter receiver although it apparently can trigger the Initialization Block if removed with the battery connected

[632 Regal]

I never learned how the rear-view mirror operates in the remote locking system but since there was no change I assume its entirely passive in that there is no stored information its just a transmitter receiver although it apparently can trigger the Initialization Block if removed with the battery connected

I think the only thing the rear view mirror does is intercept the IR signal. It is wired via a plug in wire.

[Jehu]

I think the only thing the rear view mirror does is intercept the IR signal. It is wired via a plug in wire.

Waiting on an actuator off ebay.

Going on the suggestion one of them was damaged by the current short and is now creating a mixed signal when locking sort of maybe leaking voltage internally so when in the locked position the unlock circuit is getting juice..

although this is somewhat unclear as I thought each actuator is wired discreetly to the DWA module or the GM then the DWA which ever but that they are not wired together in any daisy chain like series.. ideas?

The alarm will trigger when it is armed though.,

Even after leaving the car battery disconnected overnight could the alarm still be armed from the time when the doors locked when I bumped the trunk actuator?

How otherwise is the alarm arming? I'll wait till I get the new actuator (rear) before replacing the DWA unit with the one from my other 540.

I'll try the new actuator in one door , then the other.. am I wrong believing what i did was unlikely to have been able to cause damage through whatever component it hit first ?

[whiskychaser]

The EDC diagrams suggest you could wipe out all the lock switches, the GM and DWA in one go but I don't think you have done that.

I got the impression you can start and drive the car around. And that the major issue is the remote doesn't work to operate the central locking or set/unset the alarm? And that the alarm goes off when you double lock the car. If that is correct, it appears the car is arming/disarming itself with the key. Which is what my E34 used to do as it never had a remote from the factory. Possible that you are setting the alarm and it goes off immediately because it is missing the rear actuator?

[Jehu]

The EDC diagrams suggest you could wipe out all the lock switches, the GM and DWA in one go but I don't think you have done that.

I got the impression you can start and drive the car around. And that the major issue is the remote doesn't work to operate the central locking or set/unset the alarm? And that the alarm goes off when you double lock the car. If that is correct, it appears the car is arming/disarming itself with the key. Which is what my E34 used to do as it never had a remote from the factory. Possible that you are setting the alarm and it goes off immediately because it is missing the rear actuator?

"the remote doesn't work to operate the central locking or set/unset the alarm?"

This developed subsequent to the original problem. I did this by wither attempting the remote initialization procedure with the door open which I inconceivably did or unplugging the trunk mounted leveling sensor though I've not read that will trigger the remote block.

"the alarm goes off when you double lock the car."

This is the big problem .

If I lock the doors hwoever that happens whether depressing the door lock button, turning the key in the door lock tumbler or when the remote was still connecting using the lock button the locks would lock then release then lock then release then lock again while setting off the alarm.. so somehow the alarm is arming and the car is acting like its being broken into..

yah it would make sense if the DWA monitors the locks via input from the actuators exclusively that there must lie the fault and the DWA is getting the unlocking signal immediately after getting the locked signal perhaps due to a bridged circuit in an actuator.

Now my new rear door actuator has arrived and I'll install it asap along with the other DWA but I think two things need to be done before I try it out.

I'll need the existing remote block cleared to get that working again and then I think I've read a new DWA requires some software controlled procedure to recognize the remote for this car.. so I am expecting a shop with the GT1 software can do both.

I gather from your post you are seeing in the schematic all actuators are connected together with nothing in-between them and they all go to the GM which then speaks to the DWA.

As for the EWS that's not a problem I just drove 350 miles.

[whiskychaser]

If the battery were flat in your remote and you used the key, the alarm would go off. So it may just monitor change of state. Get rid of the block and you may be a good way to resolving this

Edit:
These are the switches I was talking about. The part number mentioned doesn't seem to appear in realoem but you can find the Euro version under 1374458
http://bmwe32.masscom.net/johan/doorlock_microswitch/doorlock_microswitch.html

[Jehu]

Ok here is the part where I reveal the real magnitude of my decrepit condition.

The problem was nothing more than Fuse #33 7.5A was in fact blown.

Didn't check it with my glasses on until after I swapped the DWA unit and the alarm still went off..

I have a stubborn reluctance to admit to myself my eyesight is going and I simply failed to see the broken wire in the top of the fuse..

System, aside from the initialization block I caused blocking the remote locks all dorrs together normally with the key or the door button without setting off the alarm.

All this confusion because I need glasses.

Thanks a million for all the solid support and ideas... bigger fish to fry this week.

AC evap, expansion valve and drier need to go in, new Koni struts up front, valve cover gaskets and a fuel pump along with getting this remote block cleared

[whiskychaser]

I thought fuse 33 also powered the LED so not sure how it was flashing. But who cares. The main thing is that normal service has been resumed
:-)

[632 Regal]

Didn't check it with my glasses on until after I swapped the DWA unit and the alarm still went off..

I have a stubborn reluctance to admit to myself my eyesight is going and I simply failed to see the broken wire in the top of the fuse..

All this confusion because I need glasses.


Jehu, You can do eye exercises and never need glasses. Learned about this from an article about the Chinese. My sons eyes were so bad in school he couldn't read a book or chalk board, I got him an eye chart to study 5 minutes a day... He is good now but it took him a month to fix them. Just an idea because glasses never fix vision just bandaid them until they get worse, then you get stronger ones etc... JMO.