I thought I was seeing things this morning on my drive, but my speedometer/mileage display seemed to be pretty bright then faded back down. This happened as many times as I was willing to take my eyes off the road. When I parked the car and with it still running, I attempted to adjust the brightness with the left hand push button. Nothing. I could not dim or brighten it any at all either by the two methods for doing so. Known problem?

 

I have seen this issue also. I seem to remember reading elsewhere on NAM that it may be related to the automatic brightness control that that is built into the display. I asked the dealer about it when I had my '07 and they didn't know about it at that time. I haven't bothered to ask since.

 

I have since seen posts that describes this as being an automatic adjustment due to sunlight or shade. I thought that I might be able to adjust the brightness with the left pushbutton control. It did not seem to adjust up or down either way so that is why I asked. Perhaps the adjustment only works at night.

 

i just checked on my 2012 cms all4 ... the left button only dims the tach displays if the left stalk light control is on

if the left stalk light control is off, the left tach button has no effect

scott

 

Left stalk light: I'm not sure what you mean but I'll dig around in the manual.

 

the headlight switch on the left stalk

 

I know the earlier models vary brightness depending on the ambient light when the
headlights are off (there's a light sensor in the speedo dial). You can verify this with
a penlight or by shading it with your hand if you can locate the right spot on the instrument.

 

did you happen to recently get new sunglasses with expensive latest and greatest polarization?

I got some new very $$ RayBan's last year and the first few days of wearing them I thought my displays on the radio and such had gone bad. Then I also realized I could not read the credit card machine display at work when I had the glasses on, not could I read displays in my son's car . .

Seems the funky new pol'zation process can really interfere with some displays. I can't wear 'em in my 79 either - the old style window tint looks like a kid spread jelly on the glass . . .

 

Yep, getting back into the car and placing my hand over the sensor hole, I was able to see the display lighten and darken. Doing this also enabled the lighten/darken function so I guess that only works when the car thinks its dark outside.

And yes I did get some new Ray Bans recently. Today was a sunny day and I did find myself noticing the changes after coming out of shadowy places.

Mystery solved!