calipol2009

Hi,

I am having an issue with my 2007 ML350. In July of 2013 it began acting up with it's alarm. The car alarm would go off at random times, multiple times a day. Sometimes, it would go off three or four times in one hour. For a while it stopped. Now it has started acting up again.

The alarm goes off in the middle of the night and sometimes when there is a light breeze or SoCal is having strong winds. However recently we have not had any winds, and it just goes off. I have noticed it goes off in cooler weather, whether that has anything to do with it.

My mechanic friend stated it could be a loose censor in the doors. Though I am not sure.

Has anyone had this issue occur?

Let me state that I have searched the forums as well as google for a problem similar to mine. Though the alarm going off seems to be a common issue, my ML does not have all the symptoms that other people seem to have. I am able to turn the alarm off with my key. The car starts and operates normally. Everything is fine except for the power trunk close mechanism which sometimes doesn't work and with the random alarm going off.

This is an issue that has caused me to literally lose sleep since the alarm keeps going off. It has also irked my neighbors. I would greatly appreciate any feedback.

I am going to disconnect the alarm fuse, but am wondering whether anyone has had this issue and repaired it.

Thank you!

dingobarkley

Let me know if you find the problem.

1 week ago, our 2007 ML350 started doing the same thing.

Only thing I can think of is, we bought a new replacement key. The key works fine. But when we lock the car with the new key, after a while the alarm goes off. It is intermittent and unpredictable. I can turn it off with the new key, but it will sound again within a short time.

I have used the old key to turn it off. That seems to silence it. I will stop and the dealer where I bought the key and see what they say.

Is there a reset button, or can you push multiple buttons on the key to reset it? Anyone know?

glocati

Alarm Siren- common issue with the back-up batteries in them going bad/leaking and corroding the circuit board in the alarm. New alarm siren is ~$160 and easy to change. The problem runs the full gamut of benz line-up s class, SL, C class, etc. Typically the alarm is behind the right front wheel well cover.

Gpwoman

My 2007 ml350 started alarming on its own after main battery change. When I took the car to a third-party Mercedes specialist they said the ML 350 does not have an auxiliary battery, I thought this was kind of strange. Does this car have an auxiliary battery? If so by changing it will this stop the car from alarming? What could be the cause of the car alarming on its own? Where is the auxiliary battery on this vehicle?

Maj. Dundee

The aux. battery is under the right front seat alongside the main battery.

Do not use a substitute battery, get from the dealer.

Gpwoman

Maj. Dundee,

Had aux battery changed at dealer today. Car has alarmed 2 times tonight since battery change. Aggravating! When the main battery was changed, you could see the corrosion on it. I suspect the corrosion leaked enough to jeopardize the module/circuit board located down there. Will start shopping for that part now.

Maj. Dundee

GP, the main purpose of the aux. battery is, if the main battery dies and you are stuck, you can insert the key in the ign. and place it in neutral so you can be towed. It also serves as a power supply to the anti-theft system.

Because there was corrosion on the main battery does not mean that the module below it (which is the front SAM) was compromised, especially if the exposed wires did not have corrosion on them.

Before you start replacing parts at whim, I strongly suggest that you have the car scanned for codes. Unfortunately you were already at the dealer and did not have it done.

Maj. Dundee

The front SAM does not control the alarm system. It is the rear SAM that does.

Scanning the car will pinpoint the location of the problem

Gpwoman

Maj. Dundee,

Thank you! Lack of sleep because of a car alarm will cause knee jerk reactions. Saw your post at 2am, car was alarming, and noticed the key fob flash red and the alarm stopped. 5 min later fob flashed again, and car alarmed. Took fob apart, removing batteries and car is now blessedly quiet. This is an 07 I purchased Nov 16 with one fob which the panic button cover is partially ripped off. I think my fob needs replacement. In the interim I will take the fob apart at home in the evening.

Maj. Dundee

Get another key ASAP.

JonathanGLE

Same here! I have a 2007 ML350 which has an alarm system that likes to go off.... I suspect it's the key since half on the panic button it broken and I have took the key apart and cleaned it which has stopped the alarm from going off for a while now! So try taking it apart and thoroughly cleaning the board of the key and that might help!

Maj. Dundee

If you only have one key you must get another one. If you lose your one and only, having the car towed to the dealer will take five days to get another one.

esphil

I had a incident yesterday with my alarm. We had some really bad storms come thru last night and lots of loud thunder. I had my alarm get set off like 4 times. Fast forward to the middle of the night when its not raining or thundering, and my freaking alarm siren goes off at 3am randomly. I get up out of bed and go outside trying to disable it and nothing works!! I can't do anything to stop it, I start the car its still blaring. I end up having to scramble to find some wrenches and remove the battery terminal since I can't find the fuses quick enough. I leave it unplugged and go back to bed. This morning I put the battery terminal back and the horn goes off immediately again. I find the fuse and pulled it. I thought that it still went off with even the fuse removed but I can't remember. I tried it again and now it stopped. I think I pulled fuse 110 for the siren, and so far it hasn't come back on. I've never had to deal with anything that ridiculous on any car I've owned. I did some research and saw that I guess there's issues with the alarm siren. I saw some used ones on eBay but honestly I don't want to have to go thru getting woken up with a siren going off. I can't imagine what I'd do if I was somewhere away from the house and no tools and I had to drive my car like that back home to figure out what to do. I ended up just ordering a OEM one. I've only owned my car 1 month and I've already had to deal with 2 electrical things, with the bad air pump relay and now this! I never had to touch any fuses in any of my other cars or relays, I guess this is the Mercedes life!

Worren King

I'm having a similar issue. I changed the batteries out on my key fob now, mostly at night... I get these random alarm sirens going off. Never happened before. The only thing that has changed was a replacement for the key fob batteries. So I've removed the batteries from the key fob and it stops... I don't get it.

Maj. Dundee

Do you have keyless go?

Please update your profile to include the year, model, is it gas, CDI or Blue and where you live, which tells us you have right or left hand drive.