E36 3G EWS alarm problems

[wiffmaster]

Evening,

The alarm on my E36 has always been over sensitive and the slightest thing seems to set it off. This never used to be a problem, as I simply locked the car with the key itself and not the fob, so the alarm was never set.

But...last week I managed to leave the interior lights on and discharge the battery. Charged it up again, but the 3G EWS alarm now appears to automatically activate after around 30 seconds. I don't press anything on the fob - it just automatically arms itself after 30 seconds, unless you start the engine.

This 'auto arm' feature seems to be required for Thatcham Cat 1 approval, and it's mentioned in the BMW manual. So, I'm assuming that after the battery went flat, it effectively reset the system and activated the 'automatic arming' feature. Which means that my alarm now sets itself and goes off every hour or so!

It says in the manual that BMW can turn this feature on/off if I take it to the dealer, but I'd rather avoid that if possible. Can I DIY it, or is it a diagnostic software job? Also, does this mean I'm going to have to have it reprogrammed to disable 'auto arm' whenever I need to remove/change the battery!?

Cheers.

[E30M3SE]

Have a read of this.

I would want to solve the issue, which is probably down to the moveement sensor if it's going off after a hour.

If it is reprogrammed and the battery is disconnected/goes flat it will need doing again as it will default to factory settings.

Edited by E30M3SE on Saturday 16th October 13:21

[wiffmaster]

Thanks for the link. From that, it looks like reprogramming is a specialist job, so I'll have to book it into the local independent.

Chap I bought it from was honest and without me prompting, told me the alarm was faulty and not to bother setting it. He said it had spent ages at the BMW dealers and they could never figure out what was setting it off. So, they evidently just ended up disabling the 'auto arm' and he just never set it.

So, unless my independent can figure out what's causing the false alarms, I expect the only 'solution' is to disconnect it. Otherwise (as you say) the same thing will happen next time the battery is changed/discharged.

[E30M3SE]

If it is going off after a hour or so then it is probably the movement sensor, which can be unplugged from the brain quite easily to see it it solves your problem.