Alarm going off.

Hi, after locking my car with the remote after a couple of minutes the alarm will go off, if i lock using the key it will not. It's a 1993 200tdi.
Any ideas peeps or can i just turn the alarm off?

I think locking by key bypasses the alarm? If so that will explain why it doesn't go off with key

gR@HaM said:

I think locking by key bypasses the alarm? If so that will explain why it doesn't go off with key

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Cheers g that would make sense, the fob is a single button one.

When i do use the key the indicator lights and Red interior light stilt flash so i think the alarm is still setting?

The alarm is still set using key or remote, the only difference is that with a key the internal ultra-sonic movement sensor is isolated. Same for the 300 series two button fob system.

discool said:

The alarm is still set using key or remote, the only difference is that with a key the internal ultra-sonic movement sensor is isolated. Same for the 300 series two button fob system.

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So a possible fault with the ultra sonic sensors. Will locate them a check it out.

Had the same issue, I think the interior sensor was getting damp due to either sunroof or windscreen leakage, so I just disconnected it.

tetsu0san said:

Had the same issue, I think the interior sensor was getting damp due to either sunroof or windscreen leakage, so I just disconnected it.

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Ok progress nice one. Well I know the sunroofs do not leak and will have to check the windscreen but it was idle for a couple of months before I purchased it so maybe they just need time to dry out. Please tell how you disabled it? I will do that for a bit then have a play.

Just unplug Or try locking with the key and see if the fault goes away.

discool said:

Just unplug Or try locking with the key and see if the fault goes away.

Click to expand...

Have spent hours trying different combination of key and fob unlocking.

Do you mean you can just unplug the interior sensor, coause that would be ideal?

Unplug each sensor in turn to find out what's naffed, locking with key only turns off the interior sensors, ours turned out to be the bonnet sensor bent ...

Awesome advice, thanks

Problem solved. What i did was nothing, then, It fixed itself! What a car.

I think maybe as one chap said. The. Interior sensors may have been Damp from where it was sitting around for awhile.

All good now Though