MG5 anti-theft alarm keeps going off in middle of the night

[gjs]

2023 MG5 SE. The anti-theft alarm keeps going off in middle of the night. No obvious triggers for it. I’ve checked all windows, doors and boot are properly closed. Is there anything else I should look for? Is there a way to lock the car without arming the alarm?

For extra info, I noticed a couple of days ago that the rear windscreen washer is spraying into the footwell. Could this leak be messing with the electrics and triggering false alarms? The washer issue is due to be fixed in a couple of weeks at local MG garage

Further question… will disconnecting the 12v battery stop the alarm from going off?

 

[Alb]

There will be a history of what triggered the alarm but this will probably be only dealer accessible.
I don't think there is a way of locking without arming the alarm so disconnecting the battery may be the only practical short term solution.

 

[maskull]

The windscreen washer may have caused a problem though I think it best to disconnect the 12V battery for about for a minute and see if the problem persists

 

[5teep]

Do you have a dongle in the obd2 socket? leaving one in place can also cause the alarm to go off randomly.

 

[gjs]

Thanks for your replies. No dongle in the ODB socket as far as I know (not even sure what that is ).
As an interim fix, I’ve taken the fuse out for the horn, this keeps the neighbours happy! Alarms will go off but with no noise, the car will log the alarm triggers and hopefully help the garage diagnose.
I’ll try and get my appointment at the MG garage moved forward so they can look at the alarm and rear windscreen washer leak at the same time.