Step lights don't turn off - FINALLY SOLVED !! (1 Viewer)

[99toylc]

Hi Guys,

So my wife took the LX570 for running some errands and this everything I noticed that the step lights are still on with the vehicle closed and locked.

Tried to take it for a spin and see if it helps, but after parking it the problem persists.


I tried too look for answers using search button but came back with nothing... for now the battery is unplugged til tomorrow.

Any help would be greatly appreciated.

 

[bloc]

Pull your door sill trim and inspect for water around the harness.

 

[99toylc]

@bloc thank you for the suggestion - unfortunately all looks to be dry under the Plastics.

 

[99toylc]

For now I pulled the fuse #54 under the hood and the lights are off.
Does anybody know where the dimmer for these lights is located? - I wonder if that is what's wrong with them staying on

 

[99toylc]

I put the fuse back in during the last oil change to see if there is any change.
Well unfortunately the problem persists.
Does anyone have any idea where the dimmer or the timer for the dimmer is? or maybe a relay that controls how long the step lights stay on? or any other ideas how to remedy this silly thing?
The fuse #54 also controls the light on my back gate illuminating the open gate area - I miss it a little in this situation...

 

[bloc]

I put the fuse back in during the last oil change to see if there is any change.
Well unfortunately the problem persists.
Does anyone have any idea where the dimmer or the timer for the dimmer is? or maybe a relay that controls how long the step lights stay on? or any other ideas how to remedy this silly thing?
The fuse #54 also controls the light on my back gate illuminating the open gate area - I miss it a little in this situation...

I’ll dig into the EWD today or tomorrow. The 2011 in your sig I assume?

 

[99toylc]

@bloc - Yes Sir, and thank you for your help!

 

[bloc]

This one is kindof a doozy.

The lights themselves are in the second image. Appears it may be an issue in the "multiplex network body ECU" which is different than the main body control module. Into that module, the green and red MPX+/- wires are from the canbus network, the black MPX wire is from the "overhead module" which has the dome and map lights.

I'd personally suggest you get access to the FSM and do some digging. This could be a tough one to figure out. I also do remember someone having an issue like this in the past.. I know I've had to dig around and find these lights for an LX in the EWD before, because I remember finding it odd they are in the interior light section. So there may be some troubleshooting for this issue elsewhere on the board.

 

[lx200inAR]

The plug for the light to the sliders comes out from the body around the B pillar (one on each side). You could disconnect the cable there and put the fuse back in to get the other functionality back. I see you have Metaltech sliders. Did they do anything weird to the wiring when installing those? I assume the lights have worked normally for some period after the slider install?

Also, do your mirror puddle lights stay on as well, or just the slider lights?

 

[99toylc]

Thanks for the replies, guys.
Ok so the funny thing is that interior dome lights are working as they should dimming and all.

The sliders were installed by me, and they have been on for at least 2.5 years - I connected the existing step light wiring to the waterproof LED lights installed slightly above the openings in the structure of MT sliders.

I may revisit the connectors, but I soldered them on with shrinkable sleeves over them - personally I don't think they are the issue and don't even know how they could be (no power yes but constant power?)

Mirror puddle lights work as normal.

 

[bloc]

This is new behavior? Are they full brightness or dimmed when they are supposed to be off?

Just occurred to me you said LED. In another vehicle I replaced the halogen interior bulbs with LED, and they'd stay on dimly full-time. Turns out the line had just a little current on it even with the halogens, but it wasn't enough to illuminate the bulb. For much more efficient LEDs, it was.

Maybe worth looking in to..

 

[99toylc]

They are fully lit and this is a new behavior, everything worked perfectly for 2.5 years

 

[mep1811]

Are the lights operated by the door switch? If so, check the switch.

 

[99toylc]

So, apparently fuse #54 also controls remote start option - not working right now that I pulled it.

 

[lx200inAR]

Just spitballing, but most of the times in Toyotas, I think the dimmer is controlled on the ground side of the circuit. I wonder if your connections are somehow creating a ground to complete the circuit. Something like a pinched wire in the frame. That would give constant lights on bypassing the dimmer and control functions of the ECU. Either that or it’s fried in the ECU doing the same thing.

 

[99toylc]

Hey guys,
Happy New Year!
I just wanted to bring this subject back up to see if anybody has any new ideas of what is wrong with my truck.

cheers !

 

[99toylc]

Hi guys,

So, after more than a year of mystery rock lights not turning off, I have finally found the culprit and now all is well.

As it turned out the truck system turns off the curtesy lights near the running boards (which I have converted to rock lights) by using the timer system that disconnects the negative polarization on the light system itself (thru wires)

As I have connected the bases of the aluminum housings of the lights to the metal parts of the sliders (I kept the plastic collars of the mounting screws inserted), but I guess rain / snow melting water with a bit of salt corrosion made a pretty decent negative ground connection thru the frame of the truck after a while (on the back part of the light housings) and allowed for continuity of negative terminal connection and caused my issue of lights constantly staying on.

I have taken the rock lights apart and installed the rubber bases (which I passed on originally) and everything is back to normal!!

Thank you everybody who head reached out to help and I hope that my experience will help someone else out.

And I almost forgot - a large toast to @ Lx200inAR for his help on the subject !

A few pics attached to make it easier to understand:

 

[grinchy]

I kept the previous OEM lights off the steps. I need to get those plugged in and zip tied up like what you’ve done with the aftermarket.