Logic / Voltage control pin to shut off engine

[omega1]

Hi all,

I have been working on a little kit, mainly for other applications, and can see no reason why I oculdnt use it for automotive applications too, which consists of a circuit that will send you a SMS message if your car is taken without your knowledge, but you can also send SMS back to the car to stop the engine, but I need to find a logic control or voltage that I can shut off that will stop the engine (without damaging it!), can anyone point me in the right direction as to where I may be able to find such a voltage/logic/pin that will be easily accessible?

Thanks!

 

[Dieselman]

The switched live feed into the ECU would probably suffice for this.

 

[grober]

One thing to be careful of is to make sure the fuel supply to the engine is cut off at the same time. The risk is a lot of unburned fuel entering the engine without being ignited. If this reaches the catalytic converter when the car restarts and this fuel ignites it may damage the catalytic converter. This was the case on the older petrol injection systems but may not apply to the newer designs. Modern systems might also be triggered into limp home mode by this sort of "unauthorised" intervention so tread carefully !

 

[tony2311]

The switched live feed into the ECU would probably suffice for this.

Stopping the engine suddenly is not a good idea as the brakes/steering will be very very heavy, killing the fuel pump for the engine to stall eventually is good

 

[Dieselman]

Stopping the engine suddenly is not a good idea as the brakes/steering will be very very heavy, killing the fuel pump for the engine to stall eventually is good

And how is it going to make any difference.? If the fuel shutoff is activated the engine stops immediately.
Sure, steering will become heavy but the brakes will still have a reserve of servo assistance.

 

[omega1]

Great feedback, many thanks. Any further info on the fuel pump option, cabling or pinouts on what would cut the supply?

Thanks again.

 

[grober]

Sorry not familiar with your particular model--C220 CDI Avantgarde Saloon (W203) 2003 taken from your sig??

 

[Baron_Samedi]

I would forget the whole idea.

There is a reason no one has already done it and that is... safety.

I don't think you could e mark such a device. No, I am pretty sure you couldn't.

 

[Dieselman]

Any further info on the fuel pump option, cabling or pinouts on what would cut the supply?

It's a mechanical pump. Cutting the power to the stop solenoid or ECU would be the best option.

 

[paulrstaylor]

I would forget the whole idea.

There is a reason no one has already done it and that is... safety.

I don't think you could e mark such a device. No, I am pretty sure you couldn't.

Rather than cut the engine is there somthing that would throw an intermittent fault code causing the car to drop into limp home mode? The first thing someone would tend to do is try to re-start the car, so cut the fuel whan the engine is stopped?

 

[Baron_Samedi]

Limp mode at a junction...

 

[alexander patie]

i would go for the 10kg of semtex option, if under the drivers seat it should stop the car fairly pronto.

 

[omega1]

I would forget the whole idea.

There is a reason no one has already done it and that is... safety.

I don't think you could e mark such a device. No, I am pretty sure you couldn't.

I'm hardly worried about the safety of someone who has nicked my car, that said, I am of course worried about the safety of others. I have built the circuit myself and fully intend to install it in my car. I get the chance to speak to the person who has stolen it and would tell them its going to stop... Whether they pull over or not is up t them...

 

[omega1]

Rather than cut the engine is there somthing that would throw an intermittent fault code causing the car to drop into limp home mode? The first thing someone would tend to do is try to re-start the car, so cut the fuel whan the engine is stopped?

Good idea! Thanks, anyone know how I could force limp home mode?

 

[richard]

I'd consider having the facility to remotely trigger the drivers airbag ...

Admittedly a bit expensive to test - but good fun - and they won't nick a car again (and it won't seriously hurt them which would get you in a lot of trouble - they will just need new underwear)

Could you just set of a very very load siren in the passenger compartment - they would have no option but to stop and leave ?

Try 4 of these around the interior
Twin-Unit Piezo Siren : Sounders : Maplin

R

 

[omega1]

Could you just set of a very very load siren in the passenger compartment - they would have no option but to stop and leave ?

Try 4 of these around the interior
Twin-Unit Piezo Siren : Sounders : Maplin

R

Also a great idea

 

[Baron_Samedi]

I'm hardly worried about the safety of someone who has nicked my car, that said, I am of course worried about the safety of others. I have built the circuit myself and fully intend to install it in my car. I get the chance to speak to the person who has stolen it and would tell them its going to stop... Whether they pull over or not is up t them...

Who gives a rats behind about the car thief?

What happens when the stolen car is told to stop as it pulls out of a junction and gets run into by a motor cycle or something?

 

[scumbag]

There is an alarm or 2 on the market that can be activated to shut your engine down. Both require Police approval. Boht have GPS tracking.

Knowingly fitting something that can do what you suggest puts innocent people at risk, and you will be liable!

Tread carefully, very carefully unless you have the law behind you with this.


Much better to have it overide the themostat in the heated seat control. See how hot it gets beofre the scorte either pulls over, in his own time, or burst into flames.

 

[omega1]

OK, point taken about the safety implications, thank you. Maybe some strategically placed piezo sirens behind the dash/under the seats is a safer option. Failing that, anyone have a circuit for an ejector seat?! Mind, that would have saftey implications too...

 

[kth286]

would it be better to stop it starting in the first place, as soon as a door is opened without authorisation.