300 TDi immobiliser

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Superaquarama

Member
Posts
51
Hi Guys,

Our '96 Defender has a (presumably) after-market immobiliser / alarm. Yesterday it took it into its head to go off of its own accord - wasn't set and keys weren't in the ignition. Fortunately it was just at home.

Only way to stop it was to disconnect the battery. Going back to it today, as soon as I touched the battery terminal off it went again. Won't start, fob buttons have no effect.

So it seems the best thing is to remove or bypass it, but I have no idea how to even start with this. Mercifully there's no ECU, so presumably it's just simple wiring. Unfortunately I have no idea who the mfr is, other than the fob says Lucas.

Any thoughts welcome ! Thanks,

Anthony
 
Hi Guys,

Our '96 Defender has a (presumably) after-market immobiliser / alarm. Yesterday it took it into its head to go off of its own accord - wasn't set and keys weren't in the ignition. Fortunately it was just at home.

Only way to stop it was to disconnect the battery. Going back to it today, as soon as I touched the battery terminal off it went again. Won't start, fob buttons have no effect.

So it seems the best thing is to remove or bypass it, but I have no idea how to even start with this. Mercifully there's no ECU, so presumably it's just simple wiring. Unfortunately I have no idea who the mfr is, other than the fob says Lucas.

Any thoughts welcome ! Thanks,

Anthony
So you know it's not the original Land Rover one? The LR one is a green box under the dash, behind the steering column and looks like this.
IMG_5185.JPG

There's a secondary part to it called 'the spider' and it's fixed to the inside of the battery box.
If this one has been removed and an aftermarket one has been fitted, then there are not a lot of other places to easily put one.
 
Many thanks. I just assumed that it was aftermarket, so will check under the dash. Are you saying they were a standard fitment (mine's 90 County) ? Never noticed anything in the battery box, though.
 
Many thanks. I just assumed that it was aftermarket, so will check under the dash. Are you saying they were a standard fitment (mine's 90 County) ? Never noticed anything in the battery box, though.
Yes, in a 1996 County Station Wagon I'm pretty sure they were standard. The spider, which lived in the battery box, caused a lot of problems with the system as it was poorly made. The PCB had problems with dry soldered joints and would turn the immobiliser on and off randomly. People either had them bypassed or removed. Can't remember if they were Lucas units.
 
Thanks again. Yes, had a look in the battery box and there is indeed a black box on the forward-most side. Cannot see the others without removing the dash trim, but assume they're there.

So do you think this bypass gadget will get me out of the hole ? At the moment I can't use the Landie as it's er, immobilised. http://www.ebay.co.uk/itm/LAND-ROVE...764554&hash=item23542303d2:g:5wcAAOSwdGFY2pmL

Or is there some other way to get it running ? I can always pull the alarm wires to stop the din.

Actually, midway through this I found an old post on the S African 4x4 forum - incredibly comprehensive, so I've shown it below for anyone else with the same problem. I might go through this first, although it looks a bit complicated and the bypass gadget would be an easier and more elegant solution - assuming it actually works ! Here it is:

The alarm/immobiliser system of the 300Tdi consists of 3 main components :

1)The small hand transmitters
2)The alarm control module, attached to the firewall behind the speedometer, and
3)The immobiliser control module, situated inside the battery box under the front passenger seat.

You can have either of the following 3 problems :

1)Faulty hand transmitter
2)Flat battery in hand transmitter, or
3)Faulty immobiliser control module – usually a dry joint on the circuit board.

The easy part is to check/replace the battery in the handheld transmitter. Press the “unlock” button, prise it open, remove the battery, press the buttons to drain any residual power in the hand transmitter, fit the new battery, put the thing together again, and press the button a few times.

If this does not work, it is probably not the transmitter.

You were supposed to be given a 4 digit security code with your vehicle ….. In the owner’s handbook they describe how enter this code into the system. It is a time consuming task, and you have to redo it every time you want to start the vehicle. Say the code is 1234….. You open the door, climb inside, put the key in the ignition and turn it once as far as it will go, turn it off, open and close the door. Turn the key twice, open and close the door, turn the key 3 times ……

From here onwards, you do the work at your own risk !

If your alarm has been activated, you need to temporarily disable it to keep the noise down. It has 2 hooters/sirens. One is the hooters of the vehicle and you can just pull the wires. There will also be a small back-up siren inside the engine bay and you can disconnect it as well. If the alarm has not been activated, you do not have to disconnect the wires.

Now for the immobiliser ……

You need the following :

1)Screwdriver
2)Small soldering iron and solder wire
3)Insulation tape
4)Test lamp or multi-tester
5)3m length of insulated electrical wire.

OK, now you proceed as follows :

1)Open the battery compartment. The immobiliser is inside the small black metal box bolted to the front panel of the battery compartment
2)Undo the screws, and remove it
3)Inside you will see a small box.
4)If you are an electronic boffin, you can open it and re-solder all the connections
5)On the outside you will see a black plastic plug with 7 black wires running in/out of it.
6)Pull the plug off.
7)Turn the ignition key until the red lights come on.
cool.gif
Take the test lamp and find the connecter that has just become “live”. Turn the key on and off to make sure it is the right one. This is the wire that brings power to the fuel cut-off solenoid. Cut it and remove ±15mm of the plastic insulation.
9)Go to the fuel solenoid, and remove the wire bringing power to it. While you are there, make sure everything is nice and clean, free of dirt, etc. Take the 3m electrical cord and connect the one end to this wire, and the other end to the positive of the battery.
10)Go back to the black plastic plug and use your test lamp to find the connector that has now become “live”. This is the wire that takes power to the fuel cut-off solenoid. Cut it and remove ±15mm of the plastic insulation.
11)Connect the 2 wires, solder and insulate them.
12)Turn the ignition key as far as it will go – just like you would when starting the vehicle. Hold the key there.
13)Take the test lamp and find the connecter that has just become “live”. This is the wire that brings power to the starter solenoid. Cut it and remove ±15mm of the plastic insulation.
14)Go to the starter solenoid, and remove the wire bringing power to it. While you are there, make sure everything is nice and clean, free of dirt, etc. Take the 3m electrical cord and connect the one end to the wire, and the other end to the positive of the battery.
15)Go back to the black plastic plug and use your test lamp to find the connector that has now become “live”. This is the wire that takes power to the starter solenoid. Cut it and remove ±15mm of the plastic insulation.
16) Connect the 2 wires, solder and insulate them.
17) Re-connect the starter and fuel solinoid wires. Put the black plastic plug back and test that everything works as it should.
1
cool.gif
Put the immobiliser control unit back inside the black metal box and refit the screws.
19)You have now bypassed the immobiliser.

If all fails, take a box of matches and ……….

Good luck, and I trust that this will solve your problem

Johan
cool.gif
 
I'll be amazed if your spider (black box in the battery box) has survived this long without being bypassed or repaired. It'll be interesting to see if anyone adds to this thread to say that they still have the original, working perfectly well. IIRC the electronics inside the black box were a second level of security (could be the wrong term) to make the immobiliser meet Thatcham specs. Hopefully, someone will clarify this.
The cable going in to that black box goes through a rubber grommet. If you take it out you'll be able to see if the circuit board is still inside or if there is a bypass plug (as per the picture in your link) rattling around on the end of the cable.
To answer your question, when I had my bypass fitted it cured all of my immobiliser issues. My alarm and immobiliser still work.
 
Well, I've just had a look at the box and it seems just possible that I might, at least until now, have had the last surviving spider ! I could see no sign of a bypass plug, and indeed the box is still riveted together apparently per original.

I'll take it apart tomorrow if I get chance and then, if there's no plug, I'll order one and hopefully this will solve the problem.

Many thanks for the help on this, I'll report back once the link plug is installed.

Incidentally, I picked up a Landie mag whilst waiting in WHS today, and there was a long letter from somebody pretty peeved with his new £112k Rangie. Apparently the alarm wasn't of sufficiently high a Thatcham category to impress his insurers, and he had to spend another £600 odd on upgrading it. Also, the satnav (I think it was) had no card of some sort and it cost him another £49 before this became operational. He said that really when spending that amount on a car it should be fully operational from the get-go, and high earners like himself were too busy to have to get into silly little details like that - have to say I sympathise.
 
Well, I've just had a look at the box and it seems just possible that I might, at least until now, have had the last surviving spider ! I could see no sign of a bypass plug, and indeed the box is still riveted together apparently per original.

I'll take it apart tomorrow if I get chance and then, if there's no plug, I'll order one and hopefully this will solve the problem.

Many thanks for the help on this, I'll report back once the link plug is installed.

Incidentally, I picked up a Landie mag whilst waiting in WHS today, and there was a long letter from somebody pretty peeved with his new £112k Rangie. Apparently the alarm wasn't of sufficiently high a Thatcham category to impress his insurers, and he had to spend another £600 odd on upgrading it. Also, the satnav (I think it was) had no card of some sort and it cost him another £49 before this became operational. He said that really when spending that amount on a car it should be fully operational from the get-go, and high earners like himself were too busy to have to get into silly little details like that - have to say I sympathise.
It's amazing that there's still some of those circuits still operating after all these years. You must have got one of the few that were well soldered. :)
I found tapping the front of the seat box, on the other side of the spider box, could get it to work again. That was to get me home though, when it had immobilised the car when I was out and about. :rolleyes:
I hope the bypass works for you and yes, let me know how you get on. :)
 
Well, I've just had a look at the box and it seems just possible that I might, at least until now, have had the last surviving spider ! I could see no sign of a bypass plug, and indeed the box is still riveted together apparently per original.

I'll take it apart tomorrow if I get chance and then, if there's no plug, I'll order one and hopefully this will solve the problem.

Many thanks for the help on this, I'll report back once the link plug is installed.

Incidentally, I picked up a Landie mag whilst waiting in WHS today, and there was a long letter from somebody pretty peeved with his new £112k Rangie. Apparently the alarm wasn't of sufficiently high a Thatcham category to impress his insurers, and he had to spend another £600 odd on upgrading it. Also, the satnav (I think it was) had no card of some sort and it cost him another £49 before this became operational. He said that really when spending that amount on a car it should be fully operational from the get-go, and high earners like himself were too busy to have to get into silly little details like that - have to say I sympathise.
My original alarm is fully operational (96 CSW) although admittedly I did open up the immobiliser a couple of years ago to resolder the connections. I think the hardest bit of the whole job was opening the box that the immobiliser is in (had to grind the rivets off). Solder job is simple if you have basic soldering skills, just pop riveted the box lid back on and it has been 100% since then. Good point is that you can click the box for factory alarm/immobiliser fitted on your insurance renewal, may save a couple of quid!
 
Yes, tried drilling out the rivets initially but they soon started just spinning round so like you, Kwakerman, had to resort to the angle grinder. I'll perhaps have a go at re-soldering the connections once the long nights arrive.

Meanwhile, the eBay bypass gadget arrived today and was duly connected. Not a 100% cure as the alarm was still sounding off all the time as soon as the battery was connected, so I had to unplug the siren (once I found it by removing the passenger side headlight!). However, that done and the immobiliser works once more so the Landie can at least be started and driven normally.

Many thanks for the help and advice, AI, without which etc.......

Anthony
 
Yes, tried drilling out the rivets initially but they soon started just spinning round so like you, Kwakerman, had to resort to the angle grinder. I'll perhaps have a go at re-soldering the connections once the long nights arrive.

Meanwhile, the eBay bypass gadget arrived today and was duly connected. Not a 100% cure as the alarm was still sounding off all the time as soon as the battery was connected, so I had to unplug the siren (once I found it by removing the passenger side headlight!). However, that done and the immobiliser works once more so the Landie can at least be started and driven normally.

Many thanks for the help and advice, AI, without which etc.......

Anthony
Sounds like you're getting there. :)
 
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