Random Alarm - at my wits end!

[Sundaycruzer]

In your case it's probably easier to get someone with a proper scanner to check it out. If one of your modules has failed scanning will usually show which module isn't communicating with system. If all the obvious problems have been disconnected and your getting a door error that you can't fix easily, you could have a failing module or failed, wrong year or badly replaced module causing your issue. Nothing wrong with trying the basics first but at some point unless your going to buy impa or some expensive scanner your shooting in the dark. Not that disconnecting a couple of sensors to check for failure isn't common practice even for professionals. Problem is not everything can be fixed with a scanner or diagnosed properly either and unfortunately most modern mechanics are read and replace anymore so if you actually have a short in the harnesses they won't be able to "scan" that or fix it. Nuff said.


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[Aitch]

The hood pin sensor is currently unplugged, so that should not be setting off the alarm.
The interior motion sensor was disconnected by prev owner, so I connected it. Alarm with go off even when I press the ARM button twice to disarm the interior motion sensor and the tilt sensor.
By virtue of elimination, the hood pin and interior motion sensor are not the culprits - feel free to correct me if my logic is whack.

Siren is next (although this will not address the Door Open error).

I didn't have the Door Open error, but I did the same as you - disconnected hood sensor and interior motion sensor, and my alarm would still go off - the only difference was mine mainly went off when I unlocked the car after it had sat for a while. I replaced the siren and that issue went away.

With the interior motion sensor still disconnected, I will sometimes get a triggered alarm now if I leave the windows open. So I wonder if the tilt sensor is being extra sensitive. With the windows up I haven't had a random alarm since replacing the siren. If I leave the windows down, I do the double-lock with the fob to disarm the motion/tilt sensor functions.

[TireFryer]

I feel compelled to chime in here: why are you wasting your time throwing darts at a board? You should be availing yourself of the extensive onboard diagnostics our cars are capable of. Even my old E31 communicated alarm issues.

Take your car immediately to an indy mechanic or dealership to run a full diagnostic scan of your alarm system. Many indys will do this for free. The results will pinpoint the fault(s) triggering the alarm, so you can stop playing whack-a-mole. Maintenance of modern cars is almost impossible without diagnostics.

The cheapest local Indy is charging $150 to run diagnostics Other than free, what's a reasonable rate to pay for diagnostics?

[TireFryer]

I might be onto something!!!

While waiting for one of 3 local Indy's to call me when they have an opening to take my car in, I did more research and reading and came across something intriguing - so share your thoughts on this:

based on this article: http://www.meeknet.co.uk/e38/E38_Battery_Drain.htm

I thought, hmmmm.... I wonder if the BMW phone battery is old and discharges when the car is not running, and in doing so, begins to draw power from the battery when car is not running. Thus, over a matter of a few hours, due to this parasitic draw to keep the cell phone battery charge up, the car battery charge drops enough to trigger the alarm?

I unplugged the cell phone (Motorola TimePort 8767) and going on 15hrs without alarm being triggered! Hope this resolves this issue. IF not, then off to an Indy when they call.

-B

[TireFryer]

****UPDATE****
Unplugging the phone did NOT solve the problem.

[racer2086]

Did you fix the driver's side latch?

[TireFryer]

Did you fix the driver's side latch?

I replaced the DS door module and I have not had the "Door Open" warnings since - should i still replace the latch?
I have lubricated all door latches/paddles 3x now over the past few weeks, but have not actually gone through and taken apart the door panels to inspect/replace the door latches.
Can you point me to "how to do it" for this?
I am awaiting call from local Indy to drop the car off for them to hook it up and track down any error codes in the system

[Sundaycruzer]

So the way our cars door trigger works is normally open , which means that when the door is closed it sends a ground to the lighting module the fast way to check is to ground the trigger wire from the door module and see if your problem goes away, that would tell you it's the door latch or door module, if it shows that the doors open, you have a broken wire some where


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[TireFryer]

So the way our cars door trigger works is normally open , which means that when the door is closed it sends a ground to the lighting module the fast way to check is to ground the trigger wire from the door module and see if your problem goes away, that would tell you it's the door latch or door module, if it shows that the doors open, you have a broken wire some where


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I read the words you have typed but being that I can be a dunce when it comes to electronic talk, any more specifics or pics would be greatly appreciated!

[TireFryer]

would position of the striker plate have anything to do with system thinking the door is open (or loose) once the system is armed? Reason I ask, all striker plates line up with the hash mark on the plate and the mounting surface... except for the driver door. The striker plate for the driver door is set about 2mm past the alignment hash mark (towards the driver seat) on the mounting surface... might be totally irrelevant, but thought I would ask.

[Sundaycruzer]

would position of the striker plate have anything to do with system thinking the door is open (or loose) once the system is armed? Reason I ask, all striker plates line up with the hash mark on the plate and the mounting surface... except for the driver door. The striker plate for the driver door is set about 2mm past the alignment hash mark (towards the driver seat) on the mounting surface... might be totally irrelevant, but thought I would ask.

That's from the parts wearing out, i.e. Rubber, etc. I'll try to give you some better info on how to ground the door trigger to check for a bad wire


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[TireFryer]

That's from the parts wearing out, i.e. Rubber, etc. I'll try to give you some better info on how to ground the door trigger to check for a bad wire


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Thank you.

I believe I have it isolated to a door switch or something in that area. Yesterday, the "door open" warning popped up again, so I took some electrical tape, and put 3 layers on top of each other. Then I cut and put this 3x layer of electrical tape on the latch pin "head", which would depress the door switch. I did this on all 4 door latch pin "heads". Car has been silent since and I hope it stays that way.

20170831_082003.jpg

Soooo... how do I test which of the 4 door switches is the culprit without disassembling each door and pulling the entire latch out (if possible)?

TIA!

-B

[Sundaycruzer]

Sounds like you should take the tape off one door at a time till you find the culprit, but having said that the striker that is moved back would be the most obvious one to replace


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[racer2086]

I don't think the tape is going to tell you anything. Each door latch has a micro switch in it that will trip when the latch is closed. You can close the switch with your finger while the door is open and it should trip the microswitch to flag the door as closed.

The easiest way to see which door it is would be to hook up INPA to the car. It will show you which door/window/lock is open. From the sound of it, you don't have any software, so that would be an issue.

My guess is that the door that causes the intermittent "door open" warning would also read "door closed" with the door being open (i.e. the micro switch in the door is sticking or a wire is shorting). What I'm thinking is you could drive the car with one door at a time latched but not fully closed. The car should throw the door open warning. Whichever door is not fully latched and not throwing the warning would likely be your culprit. HOWEVER, I would not say this would be a definitive test if everything checks out ok. You may get lucky and find the door, but if everything acts ok, I would still think you have a door switch or door wiring problem based on your intermittent door open messages.

[TireFryer]

Anyone local with INPA to help out a floundering E38'er? I pay in beer, food, spare parts and day the the range!

[Frankie]

When I search for an independent BMW shop around Perry, MI, I get 6 results within 50 miles. Have you tried calling one of them to see if they'd scan your car (for free)?

See: Bimmershops.com.

[TireFryer]

When I search for an independent BMW shop around Perry, MI, I get 6 results within 50 miles. Have you tried calling one of them to see if they'd scan your car (for free)?

See: Bimmershops.com.

I have called 4 shops, and 2 of them were out till next week for taking in new work. One told me this is beyond their ability and they'll try to diagnose it but no guarantee. Last one is quite a ways away, and I would have driven there, but I believe I have solved my problem.

No alarm for past 2 days since I added the tape to the striker pin head, which pushes the door switch closed. Going through wiring diagrams to see how I can test each one to determine which is the bad switch - I am putting money on the driver door.

I will post my findings. If anyone can share insights into testing the door switch, I am all ears.

Thanks all!

[Sundaycruzer]

Haven't had time too get you wire pin sorry


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[TireFryer]

Haven't had time too get you wire pin sorry


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No false alarm in several days since I taped up the latch pin head - so I have confirmed it is a faulty door switch. Just need to figure which one once I know how to test each switch.

[Aitch]

No false alarm in several days since I taped up the latch pin head - so I have confirmed it is a faulty door switch. Just need to figure which one once I know how to test each switch.

Un-tape them one at a time until the alarm triggering returns.

[TireFryer]

Sorry for not posting any updates... since I don't have any. Been traveling a ton (in/out of state) and have barely driven the car at all. One thing I have noticed and it is very consistent - when the outside temps get over 80deg(F), the alarm getting tripped is 100% guaranteed! However, when the temps remain below 80deg(F), the car sits quietly without so much as a whisper! Now, when I make this statement, I am talking about the car is in the same position, has NOT been driven, doors have NOT been opened and closed - just parked in the same spot, and over the course of 5 days, this is exactly what happened like clockwork. A couple of days, cooler weather = no alarm triggered. 3 days of temps above 80deg(F) = alarm triggered - even after disarming and rearming again. Once the temp dipped below 80deg(F) and car interior cooled down, quiet as a mouse!!!

Might this indicate an issue with a general control module? I have replaced the driver side window/lock module (PM-FT) with a working unit, but problem persists. Only other module I can think off which might be causing issues in the GM3 module.

Are gremlins which pop up only during periods of exposure to heat related to bad, weak or broken solder joints? thoughts?

-TIA

UPDATE: Spoke briefly with Scot from www.bmwgm5.com/GM3_Info.htm and he said, it's not a GM3 issue, so back to troubleshooting.

Anyone local (Mid-Michigan) with software to help me scan modules to track codes?

Thanks.

[shenofjo]

I hate being the guy to tell you to change out a part because this happened to me once. But this is one of the simplest parts to replace. Reason being these siren internal batteries only last so long. I also did have driver side door open signal a bunch of times before I changed the siren. I was seeing some temp related causes before and just overall random at times. Long story short, sooner or later you will need to change out the siren. I happened upon a newer model than mine in a pick n pull so I snatched a 2001 siren and I have not had any issues since ~2 years. You can get a junkyard one for cheap or get a new one. Good luck!

edit: read you actually replaced the siren already. Sorry man. Keep fighting the good fight before your spouse tells you to get rid of it

[Sundaycruzer]

Your still fighting this? Have you left the proximity sensor unplugged? In the roof behind the sunroof


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[TireFryer]

Your still fighting this? Have you left the proximity sensor unplugged? In the roof behind the sunroof


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it is plugged in, but even when I had the proximity sensor unplugged, as well as the hood sensor and 2x the arm button when setting the alarm (to disengage these sensors), the alarm still got triggered. I have not done anything with tilt sensor, but will check that as well, but with 2x the arm button, that too should be disabled.

-B

[racer2086]

Did you ever address the latch issues that were giving the door open messages? The faulty microswitch is likely your issue.