Alarm Failure, 2 Button Key Fob Type..... And How To Fix.

[simontaylor]

I have a 95 MkIII LS400 :) and on Saturday the key fob would not unlock the car :o . The key would open the door but the alarm went off (although I could turn off the siren under the bonnet) and the engine was imobolised (would not start, just completely dead, but all lights worked etc).

I tried a few things, (lock, unlock, checked all interior lights working, Battery ok etc.) called Lexus, but as it was Saturday not much could be done as the full tech team were not available.

But today, I am one of the happiest people in the world :D :D :D , and probably a good few hundred pounds better off.

My LS400 has a square remote with 2 buttons. The black button activates and locks or deactivates and unlocks the car. There is a red LED which comes on when the black button is pressed. The red button is a panic bitton which can sound the alarm, there is a slider switch on one side (for turning on/off the in car motion sensors) and a 3 pin connector on the other side (probably for programming).

It seems that '95 and '96 cars have a Scorpion T5000 alarm and imoboliser fitted to them. They are individually matched with the 2 original key fobs (but I only have 1), so if 1 part of the system fails, all 3 (alarm, imoboliser and key fobs) need to be replaced. Economically, it is easier to discard it and just fit a complete new 'aftermarket' system, especially as Scropion ceased trading a couple of years ago, but have since started up again. http://www.scorpionauto.com/keyfobs.html

GREAT NEWS, spoke with Colin Searl, the service manager at Lexus Guildford and a very helpfull man, he was a tech in '95 and he fixed it over the phone for me. Under his instruction, all I did was to slide the key fob slider up and down a couple of times and HEY PRESTO, the car unlocked itself and now I can start the engine. All fixed. It seems that if the slider is not fully at one end of it's travel, then problems can occur. Perhaps this happened while it was in my pocket.

Oh yes, this is why I drive an LS400, Great car, Great service and Great value (actually I nearly bought another LS400, just as an interim to get me to work).

:) :D :) :D :)

[GoldfingerLS]

Hey good to hear you got it resolved quickly.

Thanks for posting this up, I’m sure this could help other people who are caught in this kind of very frustrating situation.

Oh and remeber not to forget to connect the siren up again under the bonnet ;)

[simontaylor]

Good point GoldfingerLS, I'll just go that right now.

Infact, with the siren off, the car does NOT bleep 3 times when the alarm is enabled.

Also, an easy way to tell if the incar ultrasonic motion sensors are enabled, is the number of flashes from the indicators when the car is locked. 2=off and 3=on and this is controlled by the slider switch on the remote control. A good feature for only enableing the imoboliser, and not the alarm, while leaving pets etc in the car.

[John Lawley]

hmmmm this is the problem i have at the moment, what did you do just stand outside the car while moving the slider backwards and forwards while pressing the black button?

seems scorpion have gone again or at least that link doesn't work :(

[John Lawley]

Doh! doesn't work, am i looking at a whole new alarm system to be fitted after removal of the current one? why couldn't the wife have done this BEFORE the MOT and starter motor change? I could of bought a bloody LS430 at the amount it's cost me the last 2 bloody months!

[John Lawley]

Fixed!

If your scorpion alarm stops you starting the last ditch to try fixing it is to open the car, put the key in the ignition(the alarm will sound), turn to acc (or whatever last position before engine start is) open drivers window, open bonnet, disconnect Battery, wait 2 mins, reconnect Battery then turn key to off remove from ignition then plip the remote. if this fails then it's a new system :(

thanks to tony at scorpion for the procedure.

[simontaylor]

John,

The problem with mine was just that the slider (for silent / blipping mode) was set in the middle.

I did have another problem when the Battery went completely dead. After a recharge the alarm was activated, probably because it thought that the car had had the Battery disconnected by a theif. Scorpion were no help at all, just said that the fob re programming machine died so they chucked it out.

I "think" I fixed it the second time by connecting Battery, holding fob button for 10 secs while pointing at widscreen, (to re-synch fob with car) and then locked car with fob, unlocked it and it started. or something like that.

Well done John,