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Alarm randomly going off- What the????
Thread Starter
Newbie
Joined: Jun 2010
Posts: 12
Likes: 0
From: Gaithersburg MD
2008 C300 4 Matic Sport
Alarm randomly going off- What the????
This morning at around 5am the alarm in my C300 4Matic Sport decided to go off, despite there being no animal or human interaction with the car. (We live in a fairly nice neighborhood, and the car was parked behind the house with no visable signs of anyone trying to break into it.) I went out to the car and hit lock and unlock which silenced the alarm for about 15 seconds. Where it started again. I tried to hit the Panic button which again silenced it for about 15 seconds. I opened the drivers side car door and put the key in the ignition and turned it to the ON position without actually starting it, which silenced it the entire time the key was in the ignition. However as soon as I removed it with the door open or closed the alarm resumed. I started the car, closed the door, locked the doors. Then turned off the engine, removed the key and opened the door. Then I closed the door and locked it, which appeared to work... for about 3 minutes. I opened and closed all the doors on the car, tried locking it with the actual key in the drivers side door handle and this still did not resolve the issue. After all of this, and about an hour's worth of pre-dawn troubleshooting I ended up disconnecting the battery for the rest of the morning. When I left for work I reconnected the battery terminal and started her up and drove the 4 miles to my office. Everything's been ok since, but it's a strange scenario and I'd rather not have it happen again anytime soon.
Anyone had this happen to them? Any ideas on what it could be? I was thinking that perhaps there was a glitch in the electrical system that could have caused this. I just replaced both fog lamp bulbs- with the correct voltage/model that was in it before just 3 days ago. I also replaced the batteries in one of my key fobs that was dead about a week ago. But I've been using the secondary one since the first died about 2 weeks ago. So I'm not sure if either of those things could possibly have caused it. Of course taking it to the dealership and explaining the situation probably will not resolve it, and I'd rather not waste the $ on having someone tell me they can't replicate it and cant do anything about it.
It's never happened before and let's hope it doenst happen again. I've got new wheels, tires, LED eyebrow lights, and a few other modifications on the way. I'd hate to have to cancel all that and just upgrade to the new 2012 C300...
Anyone had this happen to them? Any ideas on what it could be? I was thinking that perhaps there was a glitch in the electrical system that could have caused this. I just replaced both fog lamp bulbs- with the correct voltage/model that was in it before just 3 days ago. I also replaced the batteries in one of my key fobs that was dead about a week ago. But I've been using the secondary one since the first died about 2 weeks ago. So I'm not sure if either of those things could possibly have caused it. Of course taking it to the dealership and explaining the situation probably will not resolve it, and I'd rather not waste the $ on having someone tell me they can't replicate it and cant do anything about it.
It's never happened before and let's hope it doenst happen again. I've got new wheels, tires, LED eyebrow lights, and a few other modifications on the way. I'd hate to have to cancel all that and just upgrade to the new 2012 C300...
Thread Starter
Newbie
Joined: Jun 2010
Posts: 12
Likes: 0
From: Gaithersburg MD
2008 C300 4 Matic Sport
Senior Member
Joined: Jun 2009
Posts: 396
Likes: 0
From: Inland Empire, CA
C300, 330i, MDX
This morning at around 5am the alarm in my C300 4Matic Sport decided to go off, despite there being no animal or human interaction with the car. (We live in a fairly nice neighborhood, and the car was parked behind the house with no visable signs of anyone trying to break into it.) I went out to the car and hit lock and unlock which silenced the alarm for about 15 seconds. Where it started again. I tried to hit the Panic button which again silenced it for about 15 seconds. I opened the drivers side car door and put the key in the ignition and turned it to the ON position without actually starting it, which silenced it the entire time the key was in the ignition. However as soon as I removed it with the door open or closed the alarm resumed. I started the car, closed the door, locked the doors. Then turned off the engine, removed the key and opened the door. Then I closed the door and locked it, which appeared to work... for about 3 minutes. I opened and closed all the doors on the car, tried locking it with the actual key in the drivers side door handle and this still did not resolve the issue. After all of this, and about an hour's worth of pre-dawn troubleshooting I ended up disconnecting the battery for the rest of the morning. When I left for work I reconnected the battery terminal and started her up and drove the 4 miles to my office. Everything's been ok since, but it's a strange scenario and I'd rather not have it happen again anytime soon.
Anyone had this happen to them? Any ideas on what it could be? I was thinking that perhaps there was a glitch in the electrical system that could have caused this. I just replaced both fog lamp bulbs- with the correct voltage/model that was in it before just 3 days ago. I also replaced the batteries in one of my key fobs that was dead about a week ago. But I've been using the secondary one since the first died about 2 weeks ago. So I'm not sure if either of those things could possibly have caused it. Of course taking it to the dealership and explaining the situation probably will not resolve it, and I'd rather not waste the $ on having someone tell me they can't replicate it and cant do anything about it.
It's never happened before and let's hope it doenst happen again. I've got new wheels, tires, LED eyebrow lights, and a few other modifications on the way. I'd hate to have to cancel all that and just upgrade to the new 2012 C300...
Anyone had this happen to them? Any ideas on what it could be? I was thinking that perhaps there was a glitch in the electrical system that could have caused this. I just replaced both fog lamp bulbs- with the correct voltage/model that was in it before just 3 days ago. I also replaced the batteries in one of my key fobs that was dead about a week ago. But I've been using the secondary one since the first died about 2 weeks ago. So I'm not sure if either of those things could possibly have caused it. Of course taking it to the dealership and explaining the situation probably will not resolve it, and I'd rather not waste the $ on having someone tell me they can't replicate it and cant do anything about it.
It's never happened before and let's hope it doenst happen again. I've got new wheels, tires, LED eyebrow lights, and a few other modifications on the way. I'd hate to have to cancel all that and just upgrade to the new 2012 C300...
