Ls400 Scorpion 5000 Alarm Removal

[BLOWKY]

Thank you to everyone who reads this.

I have owned my1995 MK111 LS400 for about 12 years and the Battery recently went flat when the immobiliser was on, at the same time both key fobs decided to pack up, one a few months ago, one now, as such the car can not be started. My question is, does anyone know for sure what has to be done to remove the Scorpion system (what wires need to be bridged) I have had assistance from a guy that used to fit alarms and with his help have identified that bridging the Violet & red/ yellow cables on the plug going into the Scorpion unit it enables the car to crank but not start so my guess is that something else is immobilising the fuel or ignition or both. I spoke with Lexus this morning and this Techi remembers doing a Scorpion 5000 removal a few years ago and had a vague recolection that 2 pairs of wires had to be connected. So any information greatfully received.

Kind Regards

Blowky.

[graham8370]

Are you sure you have to go down this road? The same happened to me a few years back, and, after calling the RAC out, he tapped into his computer to find the reset procedure and the job was done in 15 minutes (jump started from his van). I don't remember exactly what he did, but I recall it involved switching the ignition on and off in a certain sequence (waiting 6 seconds between).

If you're a member of one of the motoring organisations, give them a call out. Good Luck.

[Bluesman]

Are you sure you have to go down this road? The same happened to me a few years back, and, after calling the RAC out, he tapped into his computer to find the reset procedure and the job was done in 15 minutes (jump started from his van). I don't remember exactly what he did, but I recall it involved switching the ignition on and off in a certain sequence (waiting 6 seconds between).

If you're a member of one of the motoring organisations, give them a call out. Good Luck.

There is a thread on here that goes into great detail on how to do this and it was only recently, the last couple of weeks, I'll see if I can locate it. Mike

[BLOWKY]

Unfortunately when the fobs stop working with the immobiliser on there is nothing that can be done to un immobilise it. The only option is to remove it. I know all the re set's and have used the, turn to acc position remove neg batt lead, turn to on possition, attach neg lead, turn off, remove key and press the remote, pressing the remote is the key to it resetting, if you cant press it the system just re arms. catch 22!

[Stevie 79]

Thank you to everyone who reads this.

I have owned my1995 MK111 LS400 for about 12 years and the battery recently went flat when the immobiliser was on, at the same time both key fobs decided to pack up, one a few months ago, one now, as such the car can not be started. My question is, does anyone know for sure what has to be done to remove the Scorpion system (what wires need to be bridged) I have had assistance from a guy that used to fit alarms and with his help have identified that bridging the Violet & red/ yellow cables on the plug going into the Scorpion unit it enables the car to crank but not start so my guess is that something else is immobilising the fuel or ignition or both. I spoke with Lexus this morning and this Techi remembers doing a Scorpion 5000 removal a few years ago and had a vague recolection that 2 pairs of wires had to be connected. So any information greatfully received.

Kind Regards

Blowky.

I had the same problem last year once you get the engine to crank over your half way there, in the passenger footwell take the glove box out behind you will find the alarm there is a wire that goes to the fuel pump it runs along the side under the door sil pull the carpet back and you will see the loom the wire is taped into the loom so uncover the loom and follow the wire back to the alarm I think its black find that and bypass it and the car will start.

[Keith Bowler]

Had a similar problem with mine soon after I bought it last summer.

The car had a Clifford Cat 1 alarm fitted and when the Battery went flat I lost everythingbut fortunately for me I don't think the alarm was linked to the immobiliser.

After replacing the Battery I had the alarm stripped out as it seemed to be constantly draining the Battery.

[BLOWKY]

Thank you Gents,

Steve, when you removed yours was it a Scorpion unit? I only ask as there are 2 boxes piggybacked together, one large with the removable connectors, the other slightly smaller thats hard wired. It would be nice to know what I'm about to rip out. I have attached a photo of whats there.

Try as I might I cant find an instalation guide or wiring diagram for one of these units, I know they were fitted here in the UK as a requirement to give the car a Thatcham CAT1 certification, someone somewhere must have the info.

I guess its part and parcel of running something thats nearly 20 years old, it probably should have been in the scrappers years ago! Having owned it for so long I cant bear to let it go.

[simontaylor]

I have a copy of the user manual, but no wiring diagram.

send me a PM with your email and I will forward them to you.

When I had issues with my Scorpion 5000, the service manager at Guildfold Lexus remembered them. That was 3 years ago though.

I would expect that Thatcham could/should have lots of technical details.

I guess you have searched the other threads on here.

Good luck.

[Stevie 79]

Thank you Gents,

Steve, when you removed yours was it a Scorpion unit? I only ask as there are 2 boxes piggybacked together, one large with the removable connectors, the other slightly smaller thats hard wired. It would be nice to know what I'm about to rip out. I have attached a photo of whats there.

Try as I might I cant find an instalation guide or wiring diagram for one of these units, I know they were fitted here in the UK as a requirement to give the car a Thatcham CAT1 certification, someone somewhere must have the info.

I guess its part and parcel of running something thats nearly 20 years old, it probably should have been in the scrappers years ago! Having owned it for so long I cant bear to let it go.

Mine is still in there I never bothered taking it out Pretty sure thats the same, I went to Lexus here in Liverpool one of the mechanics told me they only fitted the Scorpion for a short while he was amazed mine had lasted so long he said they were not the best alarm Lexus fitted.

[BLOWKY]

Ha ha, it worked, the car started! two evenings outside with my knees on the ground and head in the footwell, snowing like a b@/?2&d!

For future reference the procedure is as follows.

Remove glove box

Locate alarm unit

Rip out

I joined the Violet and Red/Yellow wires together and remade one of the cuts on a brown or purple wire, couldnt quite make it out, this is on the upermost connector on the ECU. I also joined the 2 black wires together that exit the wiring loom running from front to rear and go into the smaller alarm box but ran out of time to check if this was necessary, it might run without this. Central locking works off the key.

Thanks to all concerned.

Blowky.

[abs66]

Lets hope there are no Lexus thieves reading this :-\

[BLOWKY]

Hello Pete,

Anyone that wants to pinch a 1995 to 1996 LS400 that was fitted with these Scorpion units must be pretty sad, I would at least go for a 97 to 98 model! To deter most thieves all you need is to leave the tank nearly empty with a little sticker on the window indicating how much a tank full of gas is, that should do the trick.

[cruisermark]

I started with a Mark 3 then the Mark 4 and now and LS430 and ive got to say i think the Mark 3 has the best looking body! - the curves are so nice! and the alloys really go well together - it just look as if the car is gliding along when i see one go past.

[BLOWKY]

Hello Mark,

I couldnt agree more. I nearly bought a 430 years ago but sorry, those headlights just dont look right. I remember the LS being launched back in 1989 or thearabouts in OZ and thought one day I will have one of those. I purchased my MK3 about 12 years ago and now cant get rid of it, apart from the fact its worth nothing these days, I did pay big money so as long as its sat there it almost represents what I paid, twisted logic maybe. Apart from that I refurbed the starter motor last year, the car will not go until the mental and physical scars have gone.

I have loved this car like no other, even the Porsche sat in the garage doesnt get treated like the lexus, its old fat, thirsty, is starting to look its age and will no doubt require surgery at some point in time, a little bit like it's owner!

My Wife has said, its either me or the car(s). Close the door on your way out.

Steve.

[abs66]

Haha . I was of course being a little tongue in cheek. I love the sticker idea......."The tank is empty, have you got 100 quid to fill it?"

Best deterrent ever Lmao. Genius.

[1Tahir]

Thank you to everyone who's contributed to this thread (sorry to resurrect it).

I too have the same problem with my 1995 LS400.

I have removed the Scorpion Unit after the helpful advice here :hocus-pokus:

The engine turns but does not start.

I have joined the Violet and Red/Yellow wires together and remade one of the cuts near the ECU, but I am having problems tracing the last wire to be re-connected. In the Scorpion Install guide the wire concerned is green (i think).

I would appreciate any help. Thanks in advance.

[Tulpen]

Gents,

I posted previously how to get round this problem on a Scorpion alarm. I'm just about to run out the door so, if you check my previous posts, you'll find it. If it hasn't been found by the time I get back (this afternoon) I'll re-post.

[1Tahir]

Thanks Tulpen for your quick reply. I've just had a quick look through your posts, but was unable to find the info.

You're help would be most appreciated!

[royzels]

Hello All.. I too had problems with my Alarm on my 1995 ls400.. I eventually had it removed by Lexus, I think at Dumfries Area.. Cost me £100.. No troubles since

[Tulpen]

Hi Tahir,

Sorry for the delay, yesterday morning took longer than I thought :(

I've read this thread very carefully and the problems I had are not the same as you have, although I did have the Scorpion alarm and it worked very well for 15 years.

I, habitually, had to leave my LS 400 in airport car parks for extended periods and suffered flat batteries as a result. The first 2 times it happened I called out the Dutch equivalent of the AA/RAC and, after a lot of trouble, they managed to get the car going. The real problem was the fact that the power for the fuel pump is routed through the alarm (that may be why you can turn yours over but it won't fire up).

I decided that all this hassle was unacceptable and there had to be an easier way to reset everything after a flat Battery. After a lot of experimentation, this is the solution I came up with...........

I realised that what the alarm wanted, was to be put back into the situation it was in before the Battery became flat. In my case this was: all doors, bonnet and boot closed, and locked using the key fob. Finding the Battery flat, I had to manually unlock the door.......this messed up the alarm logic.

So, I bought one of those portable emergency start batteries and left it in the boot. I made up two leads of thin wire (each about 3m long) with mini crocodile clips on the ends.

When I found the Battery flat, I opened the car using the ignition key. After lifting the bonnet, I attached the two thin leads to the Battery terminals then closed all the doors, boot, and bonnet - leaving the thin wires hanging out the front I attached the other ends of the thin wires to the emergency start Battery and, with a bit of power restored, could now lock the car using the key fob.

The car was now in the situation that I had left it!!!!

I opened the door using the fob, lifted the bonnet, disconnected the thin wires and, using PROPER JUMP LEADS, started the car. I had to do this quite a few times during the time I had the car, and it never failed.

It does seem, however, that your problem may be more alarm oriented rather than Battery. Before spending a lot of time on this, it might be an idea to connect the alarm again and give my method a try.

[royzels]

Hi, Thanks for that information, I'll give that a try...... Cheers Roy.

[1Tahir]

Thanks royzels & Brian,

I like the idea Brian, however I have cut out the Scorpion unit.

The engine turns but does not start.

There is one more cut that needs to be remade - only if I could find it

Added image!

[Tulpen]

Tahir,

Sorry I couldn't be more help. I think you might find that the wire you are looking for is the power for the fuel pump. Unfortunately, I don't have wiring diagrams, but I'm sure that someone else on the forum will.

[BLOWKY]

Hello Tahir,

You need to join the two black wires together that run front to back the length of the car in the passenger foot well, if memory serves removing the kick plate and pulling the carpet back will reveal the two black wires, just join these together. I think this puts power on the fuel pump. I had the same situation, engine cranks but will not start, this solved the problem.

Let me know how you get on.

Regards

Blowky.

[Tulpen]

Blowky,

I think you've hit the nail on the head. I remember, one of the times I called out the Dutch AA/RAC, the guy removed the passenger side kick plate and pushed a safety pin through two of the wires to get the fuel pump to work.