Auto Headlight Malfunction

Spurshot · October 26, 2009

On the way to work this morning, I noticed the dashlights were dim and I started playing with the dashlight dimmer to no avail. It seemed that it was in the "night" mode even though direct sunlight was shining on the dash sensor. I'm guessing, but don't know, that the headlights were in the night, full power, mode as well. After driving nearly half an hour, the "daylight" mode finally kicked in and the dash lights brightened.

Is this a symptom of a failing light sensor? Loose connectionSome other component failure?

Thanks in advance

Johnson8537 · October 26, 2009

On the way to work this morning, I noticed the dashlights were dim and I started playing with the dashlight dimmer to no avail. It seemed that it was in the "night" mode even though direct sunlight was shining on the dash sensor. I'm guessing, but don't know, that the headlights were in the night, full power, mode as well. After driving nearly half an hour, the "daylight" mode finally kicked in and the dash lights brightened.

Is this a symptom of a failing light sensor? Loose connectionSome other component failure?

Thanks in advance

Mine also does that somedays... let us know what you find out... ( I wish i could help but don't have an answer.)

My truck oftens does it when i pull out of the garage and it take about a 1/2 mile or so to go back to normal.

emwolb469 · October 26, 2009

Mine does that also...The truck turns on the lights as if it is night time, I dont know why???? It will turn on and then turn off after a while.

tjcbenz · October 26, 2009

Another example of useless "technology" that obviously doesn't work as well as a good ol' fashioned human being. I deactivated my auto-on lights. When my eyeballs sense it's too dark it sends a signal to my brain which sends a signal to my left hand to reach towards the left side of the dash and turn that knob 90 degrees. Works every time!

Deactivate that crap...it's possible on an OBS, there's gotta be a way to do it on a NBS.

dlewis1111 · October 27, 2009

On the way to work this morning, I noticed the dashlights were dim and I started playing with the dashlight dimmer to no avail. It seemed that it was in the "night" mode even though direct sunlight was shining on the dash sensor. I'm guessing, but don't know, that the headlights were in the night, full power, mode as well. After driving nearly half an hour, the "daylight" mode finally kicked in and the dash lights brightened.

Is this a symptom of a failing light sensor? Loose connectionSome other component failure?

Thanks in advance

Mine does it too....."normal" condition

Spurshot · October 27, 2009

I even stopped, shut the engine off and restarted it. No change. I may disconnect the battery and try that.

Tsmith · October 27, 2009

My truck oftens does it when i pull out of the garage and it take about a 1/2 mile or so to go back to normal.

Mine does the exact same as yours.

dlewis1111 · October 27, 2009

I even stopped, shut the engine off and restarted it. No change. I may disconnect the battery and try that.

I am pretty sure that there is a time delay before turning off regular lights and brightening up the interior lights for daytime usage. Mine will come on in the garage and stay on for about 5-10 mins after pulling out into the ambient light. Probably a safety thing. Would be nice to know how to turn off the darn things though.

Spurshot · October 27, 2009

I think the time delay is fairly quick. My truck didn't change to daylight function for about 1/2 hr with direct sunlight on the sensor while I drove into the morning sun. That seems like a malfunction to me.

big_dawg74 · October 27, 2009

Chuck, are the NBS sensors different from the OBS sensors? On my 06, the dash lights are completely off during daylight, and on (no change in intensity unless I manually adjust) at night. I do know there is some sort of a delay built in the sensor, so the lights are not constantly changing on/off/on when in partly cloudy days, or driving through tunnels, etc. I've been stopped at an intersection waiting for traffic and noticed the lights switch from DRLs to low beam (and vice versa). Maybe because you were driving in the AM the sunlight intensity wasn't enough to trip the sensor??

superjim · October 27, 2009

I think the time delay is fairly quick. My truck didn't change to daylight function for about 1/2 hr with direct sunlight on the sensor while I drove into the morning sun. That seems like a malfunction to me.

Your truck may have a different problem than my Caddy...but I have a similar issue.

In the wintertime...it stays on too long in the morning and turns on too early in the evening.

In the summertime..it is fine.

In the summer, I can back out of the garage abd within a block or less, the lights turn off and the dash is "NORMAL"

In the winter, it may take from a few minutes to 1/2 hour for it to go to "NORMAL"

I have been complaining to Cadillac for 4 years about it.

Hasn't done any good.

Per GM... "Operating within specs."

The only thing I have been able to figure out is...it has to do with the "ANGLE" of the sun in the wintertime.

The sun is lower on the horizon and therefore does not hit the sensor on the dash with the same force that it does in the summer.

I agree that it is aggravating..but I have not found a fix for it yet.

JeffreyC · December 30, 2011

Pinging this topic to see if anyone had any other information.

My wife and I just bought a Ruby Red 2008 Tahoe LTZ with 15,000. We love it. But, I've noticed the same thing this topic talks about - the headlights seem to stay on for a long time, which makes the NAV stay in "night mode" (black background) and the DIC is hard to read. While I was driving it back cross country, eventually, like after a long time, they would go off; the instrument cluster and NAV go back to "daytime mode."

Thanks in advance for any input.

txab · December 31, 2011

Pinging this topic to see if anyone had any other information.

My wife and I just bought a Ruby Red 2008 Tahoe LTZ with 15,000. We love it. But, I've noticed the same thing this topic talks about - the headlights seem to stay on for a long time, which makes the NAV stay in "night mode" (black background) and the DIC is hard to read. While I was driving it back cross country, eventually, like after a long time, they would go off; the instrument cluster and NAV go back to "daytime mode."

Thanks in advance for any input.

One thing, make sure you don't have anything blocking light reaching the ambient light sensor, like a dashmat.

tanked_darren · December 31, 2011

My truck oftens does it when i pull out of the garage and it take about a 1/2 mile or so to go back to normal.

Mine does the exact same as yours.

There is a minute or so time delay before it will switch, reason I would think is because you don't want shadows causing your dash lights to "flicker"

Not sure what would cause the OP problems though.

I used to think tech like this was garbage, but its so handy to never touch the headlight switch, now my problem is when I get in my beater I have to remember that I have to turn the headlights on manually!

cfeiring · January 5, 2012

I have noted the same problem in my truck. Daylight and the headlights are on. I was wondering if my trucks sensor had failed.

But I see that I am not alone in my thoughts.

The idea of the angle of the sun could be the reason, but not sure as my state requires a state inspection sticker near the center bottom of the windshield that may be affecting my sensor as well.

But at night it will turn the lights on like it is designed.

If the sensor is failing are they set to failsafe by turning on the lights?

Any Gm techs out there know the answer ?

Inquiring minds want to know.