Anything in an e92 trunk area to disable the car?

Yellow Snow · 04-26-2012, 05:33 AM

I am looking to wire up a simple security switch in the trunk area that I can toggle when I park up.

It needs to be in the trunk area so as to avoid running wires up the car.

It seems that the fuel pump is the best thing to switch off to make sure the car can't be stolen, but that involves the extra wiring up to the fuse box.

Is there anything else in the rear that can be switched that will disable the car?

bmw325i · 04-26-2012, 08:19 AM

The battery. All electronics would lose their memory each time though. It's pretty much impossible (maybe even impossible) to steal these cars without the key or a tow truck.

afsar · 04-26-2012, 10:34 AM

Disconnecting battery will do exactly the opposite, it will disable factory security (almost) completely, there is a reserve battery in alarm somewhere. Also it won't work as you are thinking. If you lock your car and disconnect the battery afterwards car alarm will go off. This is how it happens in my car. Not sure how insurance will cover you if car is stolen due to non-standard security mechanism applied which bypassed the factory one.

If anything was so simple and easy to do BMW would have done that anyway, no point in reinventing the wheel. Unless this is a hobby project for school/college.

TMR · 04-26-2012, 11:32 AM

You can switch off everything and someone can still tow your car away.

bmw325i · 04-26-2012, 06:22 PM

Yeah battery definitely wouldn't work. You wouldn't even be able to lock or unlock the car. I didn't really put much thought into that.

04-26-2012, 05:33 AM	#1
Yellow Snow First Lieutenant 7 Rep 311 Posts Drives: 335d Coupe. Stock no more! Join Date: Mar 2008 Location: Newcastle iTrader: (0)	Anything in an e92 trunk area to disable the car? I am looking to wire up a simple security switch in the trunk area that I can toggle when I park up. It needs to be in the trunk area so as to avoid running wires up the car. It seems that the fuel pump is the best thing to switch off to make sure the car can't be stolen, but that involves the extra wiring up to the fuse box. Is there anything else in the rear that can be switched that will disable the car?
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04-26-2012, 08:19 AM	#2
bmw325i Major General 223 Rep 5,120 Posts Drives: 2006 BMW 325i Join Date: Oct 2010 Location: United States iTrader: (8)	The battery. All electronics would lose their memory each time though. It's pretty much impossible (maybe even impossible) to steal these cars without the key or a tow truck.
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04-26-2012, 10:34 AM	#3
afsar Lieutenant 38 Rep 405 Posts Drives: BMW X5 xDrive40d Join Date: Jul 2011 Location: London iTrader: (2)	Disconnecting battery will do exactly the opposite, it will disable factory security (almost) completely, there is a reserve battery in alarm somewhere. Also it won't work as you are thinking. If you lock your car and disconnect the battery afterwards car alarm will go off. This is how it happens in my car. Not sure how insurance will cover you if car is stolen due to non-standard security mechanism applied which bypassed the factory one. If anything was so simple and easy to do BMW would have done that anyway, no point in reinventing the wheel. Unless this is a hobby project for school/college. __________________ 650i F12 - HUD, 6WA, SLI, Logic 7, Dynamic and Adaptive Drive, Comfort Access, Soft-close, top-view, Previous X5 40d M Sports and 535d LCI
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04-26-2012, 11:32 AM	#4
TMR Brigadier General 394 Rep 3,161 Posts Drives: M3 Join Date: Jun 2008 Location: Torrance iTrader: (12)	You can switch off everything and someone can still tow your car away. __________________ 2015 M3 BPM Tuned, Eibach, Magnaflow and more www.tmrmzine.com/m3/f80 SOLD E92 Slēk Carbon Fiber Widebody M3 www.tmrmzine.com/m3/slek/ SOLD E92 335i Stage 3+ with all the toys www.tmrmzine.com/335/ SOLD E39 M5 Modded, What a great car! www.tmrmzine.com/m5/
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04-26-2012, 06:22 PM	#5
bmw325i Major General 223 Rep 5,120 Posts Drives: 2006 BMW 325i Join Date: Oct 2010 Location: United States iTrader: (8)	Yeah battery definitely wouldn't work. You wouldn't even be able to lock or unlock the car. I didn't really put much thought into that.
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