exhaustgases

2002 CLK430, it does the lights flashing when sitting on occasion and is getting more frequent. So do you access it by dropping the engine plastic underside pan, and its on the driver side unibody frame rail?
Also can it be unplugged without disconnecting the battery? As far as I know we don't have the security code for the sound system, so I'd rather not fool with the battery.
A picture would really be helpful, thanks a bunch.

exhaustgases

Okay, I read different stories on here about how to get to the alarm and disconnect it.
It took maybe 5 minutes to get it done.
There is a little plastic panel that was held by 2 screws under and behind the front bumper and just in front of the left (driverside) front tire. I removed the 2 screws and kinda twisted and slid the cover out of the way and then used a video scope to see the electrical connector and reached in and unplugged it. We'll see if it fixes the problem. And no I didn't disconnect the battery, and the doors were unlocked.
And no I didn't jack it up either, just some cardboard to lay on and a stubby Phillips screw driver for the screws. I didn't remove the alarm just unplugged it.
And thanks for all the help, what a wonderful forum.

exhaustgases

Guess I spoke too soon I just heard the lights are still doing the flashing thing.
So then don't know what was unplugged, maybe the horn didn't test it.
I'll keep this up to date on what I find out.

Just Is

I've had the same issue. To my knowledge, the issue is that these alarms have internal batteries, separate from the one in the trunk. When that battery starts to die, you'll find that the alarm starts going off at random (not sure why).

When this happened to me, I got under there and just unplugged the siren. Since then I have had no issues.

exhaustgases

Where exactly is the siren? What ever it was in that area I unplugged did not fix the problem. photo would be nice.

Just Is

Sounds like you are looking in the right spot. It's on its own bracket up in front of the front driver side wheel. It's a black plastic circle about the size of a coaster.

exhaustgases

Do you have to remove the plastic inner fender after removing the tire? I just slid that little cover out of the way and unplugged a what ever and step kid says its still flashing?

Just Is

Yep you will have to move the liner. To be fair, mine may still flash while I am not around, but I haven't noticed it. Maybe unplug the siren and reset the computer(s) by disconnecting the battery for 45 mins? I've done that a few times which may have (unknowingly) solved it.

A1EK

Guys, its not that technical.
The siren in the UK is on the passenger side at the back of the wheel arch behind the liner, (this may be the drivers side for left hand drive cars, but basically the right side wheel as you look at the engine forom front.

I have removed the sirens without any issues, the security still works and lights flash when alaam is activated, just no noise. The sirens can get wet and causes them to go faulty as its a poor place that they are fitted, you can move the siren up into the engine bay if you prefer.

Lastly to get to the sirens you can turn the wheel inwards and pull back the liner.

MarcusF

Or just drop the same lower cover that's used to access the left (from the driver's seat) front fog lamp.

Serndipity

From OP posts, #'s 1 and 2, the alarm is intermittently turning on (e.g. flashing lights/siren , randomly, for no apparent reason and is trying to turn off the siren (e.g. believing that this will also turn off the flashing lights) .

If so, the suggested solutions are incorrect.

That's because the siren and flashing lights are on the output side of the alarm system (e.g. disconnecting one output, will not shut off others).

IMHO, instead, the problem is due to either to one of many faulty alarm input sensor(s) or a faulty anti-theft brain, which I believe is integrated into the PSE (A37) module.

exhaustgases

Okay heres the deal. The thing I disconnected was the alarm, and since the car was having electrical issues the step son thought it was because I disconnected the alarm or at the time I wasn't sure. And he said he still saw the lights flash!
The engine was cutting out occasionally, and he said it was like everything went dead one time. I thought battery connections. So when he came over to reconnect the alarm, I checked the connections. The power wires that attach to the cable connecter the nut was loose and backed off. And the ground clamp was loose. Yeah fixed everything for about 2 weeks. Then it started having dead battery needing jumping issues. And ended up stopping on the freeway. The alternator was putting out over 18 volts, and kept goofing up the test machine at the autoparts store. So ended up with reman alternator and new battery, all is good now and alarm still hooked up and no flashing lights. I wonder who loosened up the battery connections? He had a place recharge the AC last august so who knows for sure. I know some places do things for simple return work, quick easy expensive fixes.

A1EK

Glad you got it sorted.
The removal of the alarm will have no influence to the rest of the car apart from not sounding. The only thing to check would be that the cable connector to the alarm was not corroded and shorting at the plug or chasis.