[94vtirozguy]

This morning i was woken with my car alarm going off lights flashing, checked it out, no codes, no one tried to break in, so reset and then back to bed, then 15 minutes later the alarm went off again, again reset and it was fine.

Has been fine the rest of the day and got home today after a long drive, and again alarm went off after being home about 20 minutes.

I have been doing some reading, and 2 culprits seem to be the hood latch or the battery is on its way out.

I tried to locate the hood sensor, however i could not find it. Anyone point me in the right direction as to where it is located, and how i can test that it is functioning correctly. I also read that cleaning the sensor with brake fluid should do the trick.

There are no codes or errors shown, and nothing to show the hood is open either.

Is there a way you can get a code from the alarm or get it to tell you which sensor triggered the alarm ?

[TheCoolX3]

I think that if it was the hood sensor you'd get a light on your dash showing that the hood was open. I'd test your battery. I bet there is a way to get alarm logs or something like that, I'll do some digging and post back with what I find.

Good Luck! don't piss the neighbors off too much

Originally Posted by 94vtirozguy

This morning i was woken with my car alarm going off lights flashing, checked it out, no codes, no one tried to break in, so reset and then back to bed, then 15 minutes later the alarm went off again, again reset and it was fine.

Has been fine the rest of the day and got home today after a long drive, and again alarm went off after being home about 20 minutes.

I have been doing some reading, and 2 culprits seem to be the hood latch or the battery is on its way out.

I tried to locate the hood sensor, however i could not find it. Anyone point me in the right direction as to where it is located, and how i can test that it is functioning correctly. I also read that cleaning the sensor with brake fluid should do the trick.

There are no codes or errors shown, and nothing to show the hood is open either.

Is there a way you can get a code from the alarm or get it to tell you which sensor triggered the alarm ?

[94vtirozguy]

As a follow up to this. I ended up replacing the battery. After battery replacement, i cleared all the codes.

Now i have 3 codes still, and the alarm still randomly starting to go off again in the last two days.

JBE Junction box eletronics - C90C85 - rain-light-solar-fogging sensor hardware fault, rain sensor (permanent)
FZD Function centre roof - 801A4C - SINE: under voltage detected in internal voltage supply (intermittent)
IHKA Integrated automatic heating/air conditioning - E7144D - signal (rain intensity, 0x226 invalid transmitter JBE (permanent)

To me it looks like the rain sensor possibly needs to be reset after battery change ? or it has died.

The 801A4C code however got me stumped and would have thought that the battery change would have resolved this.....or is this another initialization thing needed to be done for the moon roof ?

Also the alarm randomly going off, is also an issue.

[BMWZ4]

Maybe a mouse hiding in the vehicle - hides while you're in the car - gets active as soon as you've locked the car. He starts moving around and sets off the inside alarm.

Yep. It's happened.

[Riick]

Did you have the windshield replaced recently?

[94vtirozguy]

the windshield is the same as when i purchased the car months ago, before the alarm issues surfaced, and the errors with rain sensor

[Riick]

The rain sensor is attached to the windshield and must be removed when the windshield is replaced.

[94vtirozguy]

yeah i looked at pulling it apart and seeing if it is a wiring issue. Also looked at the reset procedure for the sensor.

Might give them a look at first. but would this cause the alarm to go off ?

[Qsilver7]

Originally Posted by 94vtirozguy

As a follow up to this. I ended up replacing the battery. After battery replacement, i cleared all the codes.

Now i have 3 codes still, and the alarm still randomly starting to go off again in the last two days.

1. JBE Junction box eletronics - C90C85 - rain-light-solar-fogging sensor hardware fault, rain sensor (permanent)
2. FZD Function centre roof - 801A4C - SINE: under voltage detected in internal voltage supply (intermittent)
3. IHKA Integrated automatic heating/air conditioning - E7144D - signal (rain intensity, 0x226 invalid transmitter JBE (permanent)

To me it looks like the rain sensor possibly needs to be reset after battery change ? or it has died.

The 801A4C code however got me stumped and would have thought that the battery change would have resolved this.....or is this another initialization thing needed to be done for the moon roof ?

Also the alarm randomly going off, is also an issue.

In regards to the alarm going off randomly...the list of fault codes you gave the SINE fault code would be the one related to the alarm.

(SINE = emergency power siren and tilt sensor)

Here's a direct link to the TIS that explains the SINE (interior motion sensor): https://www.newtis.info/tisv2/a/en/f...right/HI6lx4TC

Are you leaving any windows or sunroof open while the car is parked & locked?

BTW, I don't follow the X3 that much so I'm not that familiar with the engine nomenclature vs the model/engine suffix...since you don't indicate which model X3 you have...you can click the HOME (at the top left of the TIS website) and select the correct X3 model...or use the last 7 digits of your VIN...this will set the TIS site to give links/results based on your VIN or model. You can then type SINE into the search box and it will list the correct info for your model X3.

[94vtirozguy]

Yeah i double checked to make sure all windows and roof were shut.

Model is BMW F25 X3 xDrive28i SAV.

The site has some useful information thanks.

[94vtirozguy]

i can confirm that if i lock the car and then hit the lock button again (within 10 seconds), then the alarm does then not randomly go off.

So my understanding this is disabling the motion and tilt sensors but not the hood sensor. Therefore it takes a faulty hood sensor out of the equation.

How do i test the tilt sensor to see if it is faulty ?

[Ol' Fart]

This may be a long shot, but it happened with my car. Mine was acting very similar to yours. Took it to the dealer and they found nothing, about 30 minutes after I got home my alarm went off again so I called the dealer and drove back (45 minute drive). They asked me to bring both keys with me when I came back, Final result, a new key. Seems like one of the buttons on my wife's key was stuck down causing the system to stay active and draining the battery. Dealer charged the battery and replaced the key. No issues since !

[Qsilver7]

Originally Posted by 94vtirozguy

i can confirm that if i lock the car and then hit the lock button again (within 10 seconds), then the alarm does then not randomly go off.

How do i test the tilt sensor to see if it is faulty?

The TIS site says that the alarm/tilt sensor (the tilt sensor is incorporated into the alarm siren) can be tested with diagnostics...so if you have software/hardware...you should be able to pull up fault code data or test the siren. If not, you'll have to ask your local dealership to do it...of if you use an indy...have them do it if they have the software.

You can read about it at this link: https://www.newtis.info/tisv2/a/en/f...ensor/D1gc5KAz

This link details where the alarm siren/tilt sensor is located and how to access it: https://www.newtis.info/tisv2/a/en/f...ystem/F0PCS9mj

The following graphic shows an example of a siren with a tilt alarm sensor.

1 = Siren with tilt alarm sensor
2 = three‐pin plug connection

[94vtirozguy]

just an update.. nothing has changed with the car, but now the weather is warmer there are no longer any alarm issues... weird

[TheCoolX3]

I've noticed this more and more on this forum and some others, as the weather warms up, all the funky electrical issues disappear.

I wonder why that happens, so odd!

Originally Posted by 94vtirozguy

just an update.. nothing has changed with the car, but now the weather is warmer there are no longer any alarm issues... weird

[94vtirozguy]

no idea, maybe the seals shrink in the extreme cold , causing pressure differences.

[6MT_Addict]

Originally Posted by 94vtirozguy

no idea, maybe the seals shrink in the extreme cold , causing pressure differences.

More likely a battery issue. Battery performance drops the colder a battery gets.

[94vtirozguy]

happened before and after replacing the battery.

[SharpAndCunning]

Just wanted to bump this and see if you ever found a resolution to your issue?


Mine just randomly went off, and i started searching and found this thread.

[94vtirozguy]

there are /were no codes being thrown to indicate anything out of ordinary. I am now thinking it could be the change in air pressure in the car when it gets really cold at night.

What i tried this cold season was i changed the air system recirculation mode in the car to not recirculate internal cabin air but to take air from outside.

So far this cold season i have not had the alarm going off randomly at all and it has been colder temperatures. Nothing otherwise has changed in the car at all.

[SharpAndCunning]

Thanks for the fast reply!

Is your car parked outside in the winter?

I'm in Mass, and i do park in a garage, but the garage hovers around 40 degrees in the winter. Admittedly, my car is usually 78-80 in the cabin when I pull in from driving home, it could happen.

For me, the car was in the garage close to 22 hours before the alarm went off. I do usually leave my windows open a little bit, and last night I didn't though.... hmmm.

[94vtirozguy]

mine is parked outside