Alarm going off randomly - solved!

[rb1947]

I thought this may come in handy for someone in the future...

I've had problems with the alarm on my W209 CLK cab going off intermittently over the last couple of months. By last week, I'd had enough of going to bed with the keys in hand every night (I know, it takes loving your Merc to a whole new level!) so I got my local MB dealer to investigate.

Half an hour later the technician came out and told me the problem was down to me keeping loose change in the cubby hole in the armrest. Apparently the alarm in the cabriolets is microwave based and hence is susceptible to interference from metallic objects.

I must admit I was somewhat sceptical, but having removed all offending coins, I haven't had a false alarm yet! :bannana::bannana:

[carnut]

Could be, but my car has a coin holder in the armrest! = Built in random alarms?
Does your change do a dance at night thus upsetting the status quo ( not the band!) of your change just sitting there?

[television]

CLK's are one thing when it comes to alarms, and the 230 is something else

[mr. shr]

Apparently the alarm in the cabriolets is microwave based and hence is susceptible to interference from metallic objects.



Sounds like a bit of a fob off to me. I reckon they just vacummed the car out and then came up with some technical sounding solution to justify the 30 minutes labour.
I reckon if you put some lose change back in the same location, you wont have any problems.

I know, I'm such a cynic!! :rolleyes:

[Wezzel]

Mine goes off ocaisionally but it is always a spider. Usually the day after taking garden rubbish to the tip :rolleyes:

[Diesel Benz]

If I got it right, 209 CLKs have different implementations for the interior protection but all are ultrasonic. Was it an SLK using IR but R230 actually using microwave based protection.

The MB comment does not sound perfectly accurate but not completely lost either, I saw a WIS document giving a warning about coins close to a microwave sensor.