Switch Backlighting Issue

[steve2006]

For once I need to ask a question and not attempt to answer one 😀

I have a weird fault on the Celsior (LS430) in that non of the buttons light around the centre console (so AC controls etc) or the shifter when the lights are switched on at night.

I did do some research and it is a known problem, possible causes being the light sensor on top of the dash or the dimmer control but nothing confirmed as sorting it.

Looking at the diagram it appears to all be Canbus controlled, a computer to turn the lights on and off mmmmmm.

Just wondering if anyone has a similar issue before the tools and DMM come out or whether this could be diagnosed via Techstream?

 

[BigBoomer]

If you've done any work in that area, sometimes reseating the connectors fixes it. On mine I ended up cleaning all the connectors out with switch cleaner, then gave them all a smear of dielectric grease and refitted them. No problems since.

[steve2006]

Cheers George I’ll take a look, I did the tap tap test around the dash area.

Does anyone have an experience in Techstream as this is all new to me, the 1994 just needed a paper clip in the diagnostic socket but this one is presently beyond me.

Obviously I’m not looking at the “official” hardware but any let’s say “guidance” on requirements would be great fully accepted.

[BigBoomer]

My Techstream 12.00.127 is installed on an ancient Compaq laptop with 4GB RAM and Win10 (1803). It works but it is slow.
It looks like those lights are controlled by the Body ECU but there should be a way to read the value coming from the sensor somewhere in Techstream.
I'm not an expert either and you can't just browse around in the program at your leisure as it has to be connected to the car to work. 

[steve2006]

Thanks again George, I also have an ancient laptop which should be suitable, any recommendations for the supply of the interface and software?

[BigBoomer]

I bought mine from an eBay supplier. This should do the job https://www.ebay.co.uk/itm/124808047632
At first mine would not connect to the car, but it turns out I wasn't fully seating the plug in the ODB2 socket. 

[steve2006]

Cheers George thanks for your input, I purchased from the seller you recommended, took some installing as the 64 bit driver wouldn’t load and the provided link for it failed but I eventually got it downloaded from the internet.

Tried it out briefly today and did a full scan and nothing flagged apart from air suspension codes which are understandable given it no longer has it fitted.

I put my spare Battery on charge to boost the car Battery on jump leads for further diagnostics which will hopefully lead me towards the backlight issue....the only bus I fully understand is the number 93 into Alfreton so a bit of a steep learning curve for me.

[BigBoomer]

Glad it's working for you. 
I'm sure I saw something on the ClubLexus US forum about something to do with the headlight selector stalk/switch but now I can't find it.
Most articles on this point to a problem with the daylight sensors.

[steve2006]

Yes I read that article George, just trying to pin point the problem before having to rip out a lot of dash to access the sensors when there was no definitive cause confirmed.