Strange request - Cut electrics to engine?

[omega1]

Hi all,

I am planning on adding a little additional feature to my C220 (CDI Avantgarde SE) which will disable the electrics to the engine as part of an 'extra' to the standard alarm/inmobiliser. I have no problem in designing and installing the device but need to find a suitable cable/fuse/circuit to disable without causing any damage, preferably just a (low current) supply somewhere which will shut the engine off if the circuit is broken.

My question is, which circuit can I safely break without causing any damage to the engine? As mentioned, I am quite happy designing and installing the circuit I want, but do not really know enough about automotive electrics to know what can be done to cut off the engine...

Can anyone help?

Thanks in advance.

 

[whitenemesis]

I imagined that is exactly what the immobiliser did?

 

[omega1]

indeed, im sure it does, i am adding a little extra for someone that may know how the standard one already works...

 

[para alpha]

People who steal Mercs, don't drive em' away! The take them away on low-loaders/Spec-lifts. Fit a self monitoring tracking system (Coppers are not bothered). find them and kill them?

 

[lynall]

We often laugh about this very thing at work ie new recent cars and trucks with extra security or even steering wheel locks, no key equals no go full stop.

Even dropping the key can dislodge the chip inside meaning a non start situation.

Even saw a inline fuel cut of immobilizer on a 57 plate truck yesterday and i havent seen one of them for years, of course the only reason i found it was because i couldnt get the fuel to bleed up after the filter change

Pretty certain most theives are going to break into your house for the keys to start the car.

From memory in my landrover days when key put in ign and turned the body control module would electrically see the key then the bcm would tell the engine ecu to wake up and the engine ecu would tell the starter to turn, simple eh?



Lynall

 

[rf065]

I had a car where the previous owner had fitted such a device to the electric fuel pump. No power to the pump, no fuel to the engine.

I only found out about it when the car kept breaking down for no obvious reason, then we found the wiring in the boot had been altered & the connections were not very professionally done, causing the fuel pump to cut out whilst driving along the road.

Russ

 

[omega1]

Interesting comments.... So the general opinion is to not bother?

 

[Diesel Benz]

You don't mention the body style, a C200CDI comes as a 202, 203 and a 204. The older ones may have a simpler drive authorisation approach but if you cut a wire to the starter solenoid or fuel pump or similar, any simple thief can "fix" it in a short time. The modern cars disable the ECU and it is simply impossible to start the car if the ECU does not want to control the engine, even if you forced the starter motor to run.

 

[omega1]

Hi, Diesel Benz, to be honest, Im not sure. I pick it up tomorrow, from what i've been reading, i've come to the conclusion that its a 203 (C220 CDI registered in 2003). Thanks

 

[SSBB]

People who steal Mercs, don't drive em' away! The take them away on low-loaders/Spec-lifts. Fit a self monitoring tracking system (Coppers are not bothered). find them and kill them?

Your wrong Im afraid, and obviously not a 'copper'

The vast majority of high end cars are taken by means of 'Car key Burglary', at some point in the night you are awoken by the sound of your front door going in, and then confronted by at least two lowlifes in balaclava's, wielding weapons and threatening violence if the keys are not handed over. Now bearing in mind your probably naked, confused and pumping adrenaline, you are not in a position to resist. Ten seconds later your car is gone.
The thieves will either park it somewhere for a couple of days or locate the tracker and rip it out.

Yes, coppers are bothered. When a tracker signal is activated most bobbies will drop whatever mountain of paperwork theyre doing and join in the search, If the helicopter is available that will also be deployed, it too has a tracker locater.

If you have such a car. Block it in with another car. If you have a porch, Lock it. If your front door is wood, get a mortice lock fitted. Use a steering lock. In short, create as many obstacles as you can. If you have tracker, activate it immediately, then phone the police. I can assure you, a search for your car will begin straight away. Just because you dont see the police it doesnt mean theyre not there.

 

[Spinal]

Your wrong Im afraid, and obviously not a 'copper'

The vast majority of high end cars are taken by means of 'Car key Burglary', at some point in the night you are awoken by the sound of your front door going in, and then confronted by at least two lowlifes in balaclava's, wielding weapons and threatening violence if the keys are not handed over. Now bearing in mind your probably naked, confused and pumping adrenaline, you are not in a position to resist. Ten seconds later your car is gone.
The thieves will either park it somewhere for a couple of days or locate the tracker and rip it out.

Yes, coppers are bothered. When a tracker signal is activated most bobbies will drop whatever mountain of paperwork theyre doing and join in the search, If the helicopter is available that will also be deployed, it too has a tracker locater.

If you have such a car. Block it in with another car. If you have a porch, Lock it. If your front door is wood, get a mortice lock fitted. Use a steering lock. In short, create as many obstacles as you can. If you have tracker, activate it immediately, then phone the police. I can assure you, a search for your car will begin straight away. Just because you dont see the police it doesnt mean theyre not there.

Not from experience...

I was lucky, the lowlifes I met ran out the kitchen door when I woke up...

Also - the police rarely really bothers... have a look around the forum, if I remember well, there was someone with a tracker fitted and it took the police a month or more to look it up...

M.

 

[SSBB]

Not from experience...

I was lucky, the lowlifes I met ran out the kitchen door when I woke up...

Also - the police rarely really bothers... have a look around the forum, if I remember well, there was someone with a tracker fitted and it took the police a month or more to look it up...

M.

I dont understand what your saying. If a call is made to police and the crime is 'In progress', such as your experience was, then an immediate response is required. If you come back from holiday for example and tell them your cars gone off the drive, then the call is graded 'routine'. In any event, there is a 72 hour rule. in this time your call must be dealt with.
If your saying the police didn't come out for a month then it needs looking into and a complaint is justified.
How long did it take officers to arrive at your house?

 

[grober]

If its a modern car the standard security will be just fine. Balance the "desirability" of your car to its level of security. It was the new fully loaded E class coupe or S class saloon then your insurance company would be insisting on a tracker device. Otherwise sensible precautions to guard your keys are probably all that's required.

 

[BTB 500]

As above, the standard security should be fine.

 

[Will]

In full summary - a six year old W203 diesel saloon is not a particularly 'at risk' vehicle, and is already fitted with a superb MB security system that means it's virtually impossible to steal the car without the keys.

If it's going to get pinched (probably not all that likely, which is nice to know ), they'll have to break into your house for the keys, or car-jack you whilst out in it. Or remove it on a low-loader (unlikely measure for a relatively low-value car).

You'll be just fine, enjoy the car and don't worry about any of this

Will

 

[rag1873]

People who steal Mercs, don't drive em' away! The take them away on low-loaders/Spec-lifts. Fit a self monitoring tracking system (Coppers are not bothered). find them and kill them?

Obviously not a copper then!!!

Do you think people join the police to sit and do mountains of paperwork all day? Eh no!!
People join to get the thrill of catching housebreakers, foot pursuits, vehicle pursuits etc etc.... My point basically is if there is a call of an on going housebreaking or theft of a car, cops would drop everything to get there and be involved, thats when the adrenalin kicks in and the fun of the job starts! So to say that coppers are not bothered is definetely not true.

 

[omega1]

Thanks for all your comments... Interesting reading...

 

[SSBB]

Obviously not a copper then!!!

Do you think people join the police to sit and do mountains of paperwork all day? Eh no!!
People join to get the thrill of catching housebreakers, foot pursuits, vehicle pursuits etc etc.... My point basically is if there is a call of an on going housebreaking or theft of a car, cops would drop everything to get there and be involved, thats when the adrenalin kicks in and the fun of the job starts! So to say that coppers are not bothered is definetely not true.

And when youve gone over loads of garden fences, through a park, more gardens and you find him in an old coal shed under a pile of full bin bags, and he wants to fight...isnt that the best thing in the world

 

[rag1873]

And when youve gone over loads of garden fences, through a park, more gardens and you find him in an old coal shed under a pile of full bin bags, and he wants to fight...isnt that the best thing in the world

Dont think i could comment on that....

 

[stevesey]

As others have said the security is tight enough that nicking the keys is the most likely way anyone would take car. So a second immobisier (run off a hidden switch etc) could be of benefit - alternatively, just be a little more careful about where you leave the keys.

I make a point of never leaving mine near the front door and taking them upstairs with me at night. Ok it's hightly unlikely anyone is interested in my car, but avoids it being used as a getaway vehicle.