Mike246

After owning my 2011 IS250-C for a year I found a curious thing regarding the lighting for the navigation display.

I have a '98 and '14 models of the GS. In both cases the navigation display reverts to inverse video to reduce the brightness at night. It is controlled by a photosensor rather than the car lighting.

The IS250-C does not seem to do this which means the display is distracting at night.

I cannot see this referenced in the handbooks nor on the setup displays.

​​​​​​​Any comments?

ed21x

​​​​​​​Doesn't the lighting automatically revert when you turn on your headlights? I see my brightness adjust automatically when i go through an underpass, so there must be a photosensor somewhere.

Mike246

There is no night-time dimming when the lights are on and no photosensor on the dashboard.

I cannot find any reference to this in the manuals nor on the setup menus.

ed21x

Yeah, I know what you mean, but whenever I drive through an underpass/tunnel, I get a delayed response where the interior lights/dash dim, and then brighten again when I exit out. This is on a 2013 IS350c, so it seems like something is detecting the light?

Mike246

Hmm, I take your point. I'll have to take a closer look around for a photo-sensor. Does your IS-C have a satnav screen?

It may interest you to know that many Lexus models are sold here in the UK with smaller engines. IS models have 2.5 rather than 3.5. Similar for the GS range through the various models.

ed21x

Yup it does. Actually the manual does make reference to how the vehicle automatically changes the settings based on ambient light. In the Navigation Manual, page 34 "Changing between day and night mode" it does state that the car will not engage night mode if the vehicle is "in a bright area, such as outside- in direct sunlight." From reading the manual, it seems like day mode is always engaged, while night mode only occurs if both the headlight is on, and the ambient light is low.

Mike246

Well, good for you ed21x. You are spot on.

As you say, the screen goes to inverse video (night mode) when it is nightfall and the headlights are on.

What threw me is that the supplied instruction book refers to a later software than I have installed.

​​​​​​​I still haven't found out where the photosensor is but I am happier now!