2005 base C6
no trouble codes
the light sensitive part of headlight control was working perfect
today it is non functional
you can twist the lighting ring and get headlights on or off
but when headllights are off then you get "Headlamps suggested"
in DIC
can that sensor on top of dash be replaced without taking things apart?

thanks for helping

 

Are you saying that when you have it set on auto the lights don't come on?

 

later on I learned that rotating the ring would turn lights off
rotate ring again and lights would turn on
it was back and forth like that
but when lights were off then message "Headlamps suggested"
comes on

 

….when it's dark, or when the wipers aren't on?

 

everything was done on sunny day

 

Were your DRLs functioning correctly when set on auto?

 

not sure about DRL

 

My guess is this is the first fall/winter with your car, and you noticed this in the late afternoon.

Even though the sun was still shining, the lower angle of the sun, combined with the lower temps will make the car think that headlamps are supposed to be on, and they will turn on, so when you turned the headlamps off it gave you the msg.

My car does this every year, and it also takes much longer to turn the headlamps off after pulling out of the garage in the morning. During the warm months, it takes ~20-30 seconds for the headlamps to turn off, but during the winter it can take as long as 4 or 5 minutes.

 

Normal and got the same messages a few time today with the sun lower on the horizon and the DRL's turned off.

Just hit the top right hand button on the right dash pad buttons to clear the message like normal when you turn the DRL's off in the garage after starting the car to begin and doing the light stalk rotate past auto to turn them off.

Bottom line, the HVAC controller sends 5v through the sensor, and reads back what amount of voltage the sensor is allowing through via sun light to it. It the sun light hits the sensor at a low angle, it drops the voltage through the sensor down just above the normal threshold, and although it will not turn the the lights on since the sensor did not dip far enough down long enough from constant lack of direct sun light, but will give you the message instead.

So with the DLR turned off manually, isntead of the head lights just coming on for a few seconds then turning off for the brief period that the sensor did not get enough day light for a second or two, it's sends the lights suggested message isntead (since the DRL are turned off, and what is really trying to tell you is it might be a good idea to turn at least the DRL auto system back on instead).

When the sensor does not get enough light for a longer period and does drop below the voltage send back threshold for a longer enough time, then it will automatically turn the lights on isntead.

 

I was out in bright sun for 2 hours and no change

have strong urge to replace that sensor on top of dash
if it is not a big deal

 

Try disconnecting the negative battery for a little while. I have no idea if that will reset the sensor, but it's worth a shot, and doesn't cost you anything.