BMW alarms

[dombanks]

Is it likely that a battery voltage of 12.1V is the cause of my alarm going off? the damn Z has just had a new wing mirror fitted and now the alarm just doesn't want to shut up. Its random as well so will be 10 mins or 10 hrs but sure enough as day turns to night it does it at 4AM!! 

 

Its deffo not the bonnet sensor. Stoneleigh the other year saw to that (sorry peeps)

 

battery is on charge anyway as thats not normal and its only 50 quid for another one so not too much to replace if goosed. 

[Ian Kinder (Bagpuss) - Joint Peak District AO]

Shouldn't do. I'd expect a periodic chirp perhaps on arming to advise low car battery.

 

Is there anyway to interrogate which sensor is activating it?

[dombanks]

4 minutes ago, Ian Kinder (Bagpuss) - Joint Peak District AO said:

Shouldn't do. I'd expect a periodic chirp perhaps on arming to advise low car battery.

 

Is there anyway to interrogate which sensor is activating it?

I ran a scan the other week and nothing came up that jumped out but the INPA software is a misshmash of English German and codes. I've got a better idea now what to look for so will give it a whirl when the c-tec has run its course. 

 

General gist from some internet searching is physically look for water ingress and the bonnet catch first. Bonnet has been disconnected for years and the usual places that indicate water (under seats, battery box, roof sumps) are dry. I will have a deeper look under the carpets/behind the glove box. next up would be the tilt sensor and interior sensor but im not sure where they are. 

 

trying to eliminate the easy and obvious first. 

[Captain Colonial]

Sounds like something is draining the battery even when it’s switched off.  Have you checked the interior / glovebox / under bonnet / boot courtesy lights?  Does the exterior mirror have a courtesy light under it that points at the ground?  A test for a parasitic drag may be in order.  While correlation doesn’t imply causation, I’m always suspicious when something that has never happened before starts immediately after a repair.

[dombanks]

Scott, I suspect the battery low voltage is due to 2 things, the first being I completely screwed it last summer when I daftly left the ignition on whilst cleaning it and the xenon auto lights came on at dusk. Took 2 days for the ctek to "charge it"  and I used it regularly since then but given it started ok I never looked at the voltage it was storing. the second is I bet its been stop started loads in the body shop so just generally ran down. 

 

lights are a good call. 

[Captain Colonial]

35 minutes ago, dombanks said:

Scott, I suspect the battery low voltage is due to 2 things, the first being I completely screwed it last summer when I daftly left the ignition on whilst cleaning it and the xenon auto lights came on at dusk.

Yep, that would do it.  Take it round to somewhere that can do a proper battery test and see how many amp hours it has remaining vs. the rating.  If it’s down to 50% or less, it wouldn’t take much for the alarm to drag the battery down far enough to trigger it to go off due to a perceived low voltage.

 

If you use the key in the driver’s side door lock to secure it on many cars instead of the blipper, it deadlocks the doors without setting the alarm.  I had to do that on my Volvo when the alarm packed up until I could get it sorted.  Not sure if it works on BMWs though.

[dombanks]

good call, its been on the charger since 9.30 ish and is still on the orange lights so it wouldnt surprise me if its goosed. Eurocarparts has their usual offers on and a new one is £55 so nothing major. Hopefully this is it to save me having to go down ID sensors etc..time will tell