Immobilizer points/possibilities

[Grid]

It seems that you guys are having a surge in VR-4 thefts in Oz. I'd like to gather the information in one place on how to install a 2-3 point immobilizer. Without being too specific of course, to not make it easy for any thieves that might read this.

Main point of the immobilizer is to make it impossible to start the car unless a specific key/card/switch is pressed. The VR-4s do not have a in-key immobilizer like the EU Galants have. Which makes it all the more important to install an aftermarket immo.

1) Interrupt the fuel pump power
Pros: Most obvious and widely used
Cons: Hotwiring the fuel pump is braindead easy and can be done in seconds if a thief brings a small battery and some wires. LPG-enabled cars are not affected by this - if the engine is still warm, the LPG system will switch on immediatelly and probably let the car drive on with the fuel pump off.

2) Interrupt the IFS signal
Pros:
Cons:

3) Interrupt the crankshaft signal
Pros:
Cons:

4) Interrupt the ignition coil signals
Pros:
Cons: You would need to interrupt more than one. The car will still be driveable on 5 cylinders

Other ideas?

 

[pretzil]

I will be following this with great interest.

Could you interrupt the power to the ECU?
Pros: Could be much harder to locate and bypass.
Cons: possibly damaging the ECU with a voltage spike from a relay connecting? - Learning ECU's resetting after each restart if power is fully disconnected.

Btw, do they still have the GSM phone network in Poland? I could send you my old GPS tracker + remote immobiliser... GSM has been shut off here this year so its useless :'(

 

[wintertidenz]

Disrupting the cam and crank sensors will work, the car will crank but not fire. Only downside is that it will throw ECU errors when you go to read the faults.

You could relay the injectors ground signal, but not sure if that would cause issues - the relay could cause a dirtier signal unless it's a solid state relay.

Could also kill the TPS wire with a relay to make the car run like crap.

 

[Grid]

I will be following this with great interest.

Could you interrupt the power to the ECU?
Pros: Could be much harder to locate and bypass.
Cons: possibly damaging the ECU with a voltage spike from a relay connecting? - Learning ECU's resetting after each restart if power is fully disconnected.

Btw, do they still have the GSM phone network in Poland? I could send you my old GPS tracker + remote immobiliser... GSM has been shut off here this year so its useless :'(

ECU has several power lines - you can leave the permament ones alone to preserve the settings, and only block the ignition-switched ones. That could be interesting - you turn the key to ACC and no lights go on the dash at all, unless immobilizer is deactivated.

We sure still do have the GSM network, if you can part with it, sure! Main challenge is to find economic shipment, or a shipment opportunity - I order stuff from Oz from time to time

 

[wintertidenz]

The dash still lights up without an ECU just no engine lights. You can try and crank too but of course no firing happens.

 

[pretzil]

On autos would there be an input wire you could use to make the ECU think it's in gear and not start?

 

[wintertidenz]

You could immobilize off the inhibitor cabling in the loom. In manuals I'm not sure, but I suspect it either doesn't exist or is looped back in on the loom somewhere.

My thought is to either have the car run like crap, or run for two minutes then die.
If it doesn't immediately start they will know it's been tampered with, if it dies or runs like crap then they think it's a dying car and not worth it.

 

[Grid]

I just found out the hard way that the IFS carries the primary power to the coils Interrupting that stops the car dead in its tracks. It should also be possible to interrupt the ECU signal to the coils - one would be enough, car won't get anywhere on 4 cylinders.

 

[wintertidenz]

I've found that our engines WILL idle on two cylinders previously