Any auto-electricians? Immobiliser removal.

anewman

I have one of those ancient insert and remove electronic key immobilisers (by Meta Systems), that was installed by the importers of my car. I only have one key which is quite old, and it is no longer possible to get new or replacement keys. Before the key stops working or I lose it, it could be a good idea to remove the immobiliser rather than potentially end up stuck somewhere. I have thought about what the best approach might be to remove the immobiliser and hope I have got the right idea so wanted to check before I started chopping.

I have located the black box that controls it and it has about 7 black wires(excluding LED and key receptacle).

It seems the best approach would be to leave everything in place, strip a little insulation off each wire ensuring they don't touch each other or short out. Then get out a multimeter.

Determine which wires perform the following functions and label them....

+12v constant
-12v ground (tested for continuity between wire and a good ground)
+12v ignition switched (tested with key in the "on" position)

This should leave 4 wires' functions undetermined. Then with the key, turn the immobiliser off and test the remaining 4 wires for continuity. Hopefully they will pair up individually using this method - or maybe 2 wires are decoy wires? Then the task is to chop, strip and securely solder and insulate. Attempt to start the car with the immobiliser on, and if the car can be started I am successful. Then task is to remove all connections, insulate, and remove the black box.

I am not a qualified auto-electrician so I propose the above making a best guess at how the immobiliser functions. Is the above likely to work? Any suggestions on anything I may have missed? Also, should it be ok to start the car with the instrument panel removed? Thanks in advance.

Keith

I've a horrible feeling I'm going to be considering this when I fit my new engine as the car is fitted with a very similar old immobiliser.

I've removed the wiring loom from the engine bay, and not found any connections for it, so I can only assume it's all hidden behind the dash.

I'm hoping that once I fit my new engine it will run, and then ship my car to a decent garage to have this immobiliser removed and a new Cat 2 one fitted.

goldspanners

in theory it sounds good anewman,but what do the wires go to? are they controlling the fuel pump? the starter? a relay? or all of them.how many do you need to join before it will start.if you are going to try it i would label all wires,and snip them leaving plenty on each end of cut so you could rejoin them if it doesnt work,at the worst you may blow a fuse or 2 or 3 or 4 or 5 :rotfl:

good luck with it any way,your lucky it only has 7 wires,most modern retrofit ones have 30 or 40 wires.

tomstickland

Should be pretty simple. I had an old style immobiliser which I removed at 5am one morning when I found that the internals of the key had gone.
Just follow the Black wires to see which main wires they have intercepted.
The multimeter idea is a good one too.

Generally they just intercept the ignition and fuel pump lines.

Conor_3

It's really simple to bypass if it's the simple long flat key with several "pins" on it. Forget the black box. All you need to concentrate on is the plug that the key goes into.

You need a multimeter set on continuity or diode test.

On the keyfob , number mentally the pins from left to right. Place one probe on the first contact then use the other on the others one at a time. Then go to contact two with the probe that you had on the first and repeat the same. Whenever you've got continuity showing, write down both the pin numbers needed to show continuity.

At the end, you should have a list like

2-7
4-6
7-2
6-4

( the amount may vary depending on how many links are made). You then shorten the list, as, for example, 2-7 is the same as 7-2 so you only need to list 2-7.

You then need to get at the back of the plug you insert the key in and join together the wires you've got on your list so in my list, the wire going to pin 2 on the plug would be joined to pin 7 and the wire on pin 4 joined to pin 6.