Gs450H Ignition Won't Turn Off

[bbmcflurry]

I have a 2007 GS450H and after using the car an parking up the other day I pressed the start button to turn the engine off but the climate control fans stayed on and the headlights also stayed on after opening the door (They are set to automatic and should turn off at this point) I have pressed the start button multiple times and started and stopped the engine but it won't turn the electrics off.

I am also unable to lock the car with the central locking as it recognises the ignition is still turned on and have to lock it with the key, I can see the start button is illuminated as well. Eventually the Battery drained and the alarm started going off and the Battery died, I had to jump start the Battery and drove around to charge it up but when I finished it exhibited the same behaviour again.

Any ideas? anyone ever heard of anything like this before?

[Webtrans]

Hello,

The most likely cause of this type of fault is usually associated with:

A. a short circuit somewhere in the wiring loom where a permanently fed live circuit has been breached and is now making contact with an ignition or auxiliary fed circuit.

B. a short circuit in an electrical or electronic component that is also causing a permanent live feed to remain present in a normally switched service.

C. a component such as a relay or other switching device that would normally disconnect a switched service, but who's contacts have stuck or welded together, keeping the feed live.

If you feel confident enough to try to locate this problem, I would start by removing each fuse in turn until you come across one that will switch off ALL of the affected services. (not just one of them as this could be the designated fuse to that one particular component)

This is a very difficult and exact procedure that should be carried out by a qualified Auto Electrician, but if you intend to go in blind, then please take particular attention to the following points:

1) IMPORTANT! if your Battery drains to the point where you can not restart, then please, please, please...DO NOT use jump leads to try to restart. Any surge experienced by either your own car or the donor vehicle during connection could cause a catastrophic failure in any of the ECU's in either vehicle. For safety's sake, remove the Battery for bench charging - or at least, disconnect the battery's earth lead.

2) when replacing the Battery after charge, leave the earth lead connection until last.

3) when removing fuses during your diagnosis, DO NOT disconnect any fuse or component associated with the air bag system

4) be prepared for some inconvenience should the security system and immobiliser loose it's programming and prevent you from restarting due to lock-out.

5) should this problem suddenly appear to right itself, it should not be left. It will most certainly return at some point -usually at the most inconvenient time.

I am sorry if this seems to be a gloomy message, but I cannot recommend more highly, that you seek the help of a qualified auto-electrician.

Kind Regards,

Eric (Auto-Electrician)

[mr2lad]

I concur with bench charging.... I had a 08 gs450h and went to jump start my mrs car.... And must of surged as my Emv screen went all to pot , actually thought it had fried it...but sorted itself 24hrs later......

[bbmcflurry]

Thanks for the updates, off to Lexus I go then, hopefully they will be able to sort it.

I have had another electrical issue with the car where the whole center console stopped working apart from the screen and the stereo, this has been to Lexus and they couldn't figure that out, it kept coming back intermittently and going off again, not sure if linked or just symptomatic of lots of dodgy electrical work (Seems unlikely from Lexus though)

[Animal Mother]

Water ingress? DO you have a sunroof? Check all drain holes.