I have a Chevy with daytime running lights. I read the manual about the setting the dimmer on the unit by holding the mode button. Makes sense if you dont have daytime running lights... does this effect the dimmer on the 920? If i set the dimmer at night with my headlights on nearly to zero will my unit still think it's night time during the day when my daytime lights are on? I really liked how my d2 did all the dimming on its own 
DRLs do not put the AVIC into night mode if wired correctly.
DRL are not your low beam headlights. Two different things.
Well I see no difference in the day or night and it doesnt seem to be working. What should be happening? Mode and set dimmer with headlights off and do it again when they are on? There is no difference in the menu with lights on or off. Should there be? What do I need to tell my installer to fix on a GM car with DTL to make it work if it is the wiring??
On settings, there's a page that list the GPS signal, VSS pulse, etc. I don't remember if there is a stat for the dimmer signal, but if there is.. check what it does when you turn on/off the lights.
The avic illumination wire isn't connected then. The map should switch to night colors and dim when the headlights are turned on.
Under connection status there is Illumination Status, it should read "low" when the headlights are off, and "high" when the lights are on.
Under illumination it says OFF. I guess it's not connected at all? Do you think my chevy doesn't have an illumination wire in the harness? Sounds weird. If not what is the best way to get it to work on my 06 trailblazer? I'll refer to this with my installer.
Thank you so much!
It should have illumination in the harness, most cars do. If not, the installer would need to tap into the headlight switch/circuit.
You're right, illumination status should change from off to on when you turn the lights on, not low/high like I said before, that was on older units.
This is how it should operate, go to 4:50
Yeah I forgot, you can also see the sky change from day to night when looking at the map when the ILL is working correctly. Most vehicles should have an ILL on the radio harness.
Yeah I forgot, you can also see the sky change from day to night when looking at the map when the ILL is working correctly. Most vehicles should have an ILL on the radio harness.
My illumination says OFF at all times. Lights on off during the day and at night. Does that mean that it's not connected at all? If it's a basic thing how could my installer miss that? So annoying.
Yeah it's either not connected or connected to the wrong wire.
Yeah it's either not connected or connected to the wrong wire.
Did some more digging. Apparently my Chevy Trailblazer does not have a pin for the illumination. I will have to take the wire from the unit and tie it in with something else that turns on at night. Looks like the rear wiper switch will work fine. Thanks for the help.