E46 330i alarm going off randomly

[K0dAx]

Hi everyone, my alarm keeps going off randomly. It started this afternoon (car parked in the garage) and I went out to unlock it but it kept ringing. After cycling locks to reset the alarm, it kept ringing until I disconnected the battery for a while. I reconnected the battery and as soon as I opened the bonnet, it went off again (with the car unlocked).

I read somewhere that it might be the bonnet sensor so I unplugged it and went for a drive and it still rang (yes, it rang during the drive) so now it's parked again. I locked it and disabled the motion sensors (double tap lock button) and it's quiet so far. Any thoughts as to what may be causing this?

 

[Kyle]

Hmm, if it’s fine now that you’ve disabled the motion sensors then I would guess they’re the culprit.

 

[S1NGH 911]

There is a sensor/plug under the bonnet at the rear, this used to give me issues on my E39


Sent from my iPhone using Tapatalk

 

[K0dAx]

Hmm, if it’s fine now that you’ve disabled the motion sensors then I would guess they’re the culprit.

It's been quiet since I locked it so the sensors might indeed be the cause. The only sensors remaining are the interior one and the tilt one at the boot so it's a toss up between the two. What puzzles me is why it would ring the alarm when the vehicle is in motion :hammerhead:

---

There is a sensor/plug under the bonnet at the rear, this used to give me issues on my E39


Sent from my iPhone using Tapatalk

I disconnected it before I went for a drive. On the E46 it's in front of the power steering reservoir just before the positive battery terminal

 

[K0dAx]

So I visited the auto and he said the battery is good and he called some BMW mech who said that once the car is moving all sensors are disabled so it should be the GM5 module. Has anyone else experienced this due to a failing GM5 module?