Daytime running lights question


#1

2007 Chevy Impala LT1

3.5L V-6 FF engine

auto trans

6,100 miles



Neither the car’s manual or the service manager at the dealership has any info on this, maybe someone can tell me…



Why do the automatic daytime running lights sometimes stay on for about 15 to 20 seconds after the engine is shut off while at other times going off immediately when the engine is shut off?



No particular pattern as to how far the car was driven, the brightness of natural lighting outside, etc. Just sometimes the lights stay on and sometimes they don’t.



I’ve the habit of turning them off manually at times they stay on for the delayed automatic turn off.



Any ideas?



Marnet

…still asking questions & learning…


#2

Marnet,

This vehicle has a delayed automatic turn off for the DRLs?

I don’t understand your last sentence. Explain please. Wait a sec, does this vehicle have an override switch to turn on or turn off the DRLs?

As far as I know the DRLs on all GM vehicles come on only (after) the ignition key is turned on to the start position and released to the run position AND the parking brake is released.
It also must be dark enough for the dash sensor to detect this.

They go off (‘automatically’) when the ignition switch is turned off.


#3

Hi Roadrunner.

Yes, I can set the DRLs to an automatic on/off setting or turn the automatic feature off. If kept in the off position the DRLs don’t even turn on when the engine is running.

I happen to like DRLs so I keep them set to come on automatically. However, guess I just don’t trust to keep having them stay on for awhile and then shut off automatically after the engine has been shut off, I’ve exited the car, and walked away. Since most of my driving is short trips of only a few miles I can’t help thinking the battery shouldn’t have a frequent draw down from lights left on like that even though its only for long seconds at a time.

So, when I kill the engine if the DRLs don’t simultaneously shut off, I turn them off manually. Next time I start up the car, they come on again automatically.

Again, there’s no pattern to when the DRLs stay on for a few seconds or turn off automatically when the engine is killed. It can be high noon on a bright sunny day and they’ll stay on. Other times, even on dim, gloomy days they go off immediately. Not a big deal, just has me insatiably curious.

Marnet


#4

Marnet

Do you consistently use your emergency brake when you park the car? On most cars that I am familiar with, the DRLs turn off when the e-brake is applied. So, my reasoning (which, of course, could be faulty) is that perhaps you don’t always use your e-brake when you park the car.


#5

VDC, hmmmm interesting, I’ll have to pay attention to that!

I have been trying to get into the habit of using the e-brake when I park, having learned from my reading posts here over the past year and a half how that saves wear and tear on the parking pawl of the transmission (if I remember the term correctly…haven’t been on the board in some months). But sometimes I forget and don’t use the e-brake.

Now you have me curious to see if that is what makes the difference!

Thanks.

Marnet


#6

No answer for your question. Have you noticed the Chevy and GMC pickups driving around with one of the little front running lights out. I wonder why they burn out so often. It makes a vehicle look like it is cheaply made. It’s only a light bulb. My running lights seem to work alright. They don’t come on until I put the truck in gear with the parking brake released.


#7

Well, turns out the use or lack of use of the parking brake makes no difference one way or the other as to if and when the DRLs turn off on their own when the engine is turned off or stay on for a delayed 15 or so seconds after the engine is off.

Also, the DRLs always come on when the engine is started whether the e-brake is on or not. So, there is no connection between the e-brake and DRLs.

Like I said before, it’s not a big deal if the lights turn off automatically when the engine is turned off or have a delayed automatic shut off. After all, I’ve never had a car before with DRLs and am used to always turning off lights manually.

Just one of those things which sparked my curiosity.

Marnet


#8

Some GM cars, probably yours too, have an override to shut off the headlights by twisting the turn signal lever. It also can defeat the automatic headlight turn on when the photocell in the middle of your dashboard detects too little outdoor light. Are you sometines storing things on the dash that might cover the photocell to cause erratic operation? I suspect that if the photcell detects enough ambient light where you park, the headlights turn off sooner.


#9

How much ambient light there is would sound a likely determinent.

As to putting anything on the dashboard, I NEVER have anything on either the front dashboard or the rear deck. I neither want my vision forward and rear obscured nor want things where they can become airborne missles in a hard stop or sharp turn.

I do make sure the little sensor on the dash is kept clean and dusted.

But like you note, I can override the automatic DRLs, in my Impala by twisting the light switch to the left. I can also set the switch to turn on only the yellow parking lights or fully turn on the night headlights. But most of the time I simply leave it set on automatic where it knows to turn on the DRLs all the time.

Marnet


#10

I would not bet on this, but it could just be a sticky relay. The only thing that argues against that is that you can manually force them to turn off. I think some cars will leave the lights on for convenience lighting if it’s dark outside. Maybe your light sensor is going bad?


#11

I have a 2006 Chevrolet Uplander (minivan) that does the same thing. If the sun is out and I pull into a parking place that is not in the shade, the headlights do not come on. However, if the sun is out and I pull into the garage or under the shade tree in my driveway, the headlights come on for a short interval of time.

Even if it is daylight, if I back out of the garage, the headlights will be on. They remain on for a while. After I have driven a mile or so, I’ll hear a click under the dashboard and the headlights will go off and the parking lights come on. If I am driving into dusk, I’ll hear a click and the lights will go on. The dash lights come on brighter when the headlights go on, and dim when the sensor switches off the headlights.

The only disadvantage to this feature is that I’m so used to having the lights automatically come on and off that while driving a Ford Taurus last week on a trip that is company car, I would forget to turn the lights off and a warning buzzer would sound when I turned the key off.


#12

Marnet,

The DRLs on my 2000 Olds Silhouette (van) work like this: During daylight hours; starting the van with the parking brake engaged, the DRLs stay off. Once the parking brake is released, they come on.

Drive, then park, leave engine running, APPLY parking brake (or not), DRLs stay on until I turn the ignition key OFF. The DRLs turn off instantly.

Dark or low light conditions: the following happens; Start engine, DRLs come on. Parking brake applied, (as always when parked) .

RELEASE the parking brake and low light sensor activates the complete lighting system.

Travel, park with engine running and sensor keeping all lights on, apply parking brake, all lights remain on UNTIL I turn the ignition key off. Then all lights go off.

In short, YES, the parking brake works in conjunction with the DRLs and the low light sensor.

You MAY have a short in the wiring, OR like was mentioned, a faulty low light sensor.

GM vehicles made for US use do not require DRLs (with a few exceptions). Up here in Canada, they are required across the country. Perhaps this is the reason you have a switch to be able to disable the lights.

I have noticed one thing though: when the wife and I go south with our 2002 Tahoe and travel trailer and we go through the tunnel at the top of the Pennsylvania turnpike, I have to turn on the headlight switch to have instant lighting as the low light sensor DOES take a few seconds to react.
The tunnel is well lit, but the law says turn them on and that makes good safety sense to me.


#13

Triedaq

(Quote) The dash lights come on brighter when the headlights go on and dim when the sensor switches off the headlights. (Unquote)

Moot point, but I believe you meant that opposite of the way you said it. Yes?


#14

Thanks for all the feedback everyone.

Apparently the DRLs are either designed to act differently on my 2007 Impala than how they seem to act on other cars you all have been speaking of, or they are doing so for some malfunctioning cause.

Anyway, I’m going to dig out the car manual and carefully re-read everything again, in case I’ve been doing something other than recommended. (Always a possibility!)

Furthermore, I’m due to get the oil changed and tires rotated in about another 800 or so miles, so if I’ve not solved the curious mystery by then, I’ll inquire when the car is serviced.

The important point is that the lights do work without a problem and automatically turn off without a problem when kept on the automatic setting, just sometimes immediately when the engine is shut off and sometimes on the “courtesy” delay. Not being a trusting sort when the healthy life of the car’s battery is at stake, I prefer to manually override the courtesy delay and kill the lights when I turn off the engine.

Gotta admit, all the electronic gadgets such as tire pressure sensors, 2 trip odometers, avg. fuel economy, instant fuel economy, etc. etc. etc. along with cup holders…all nice to have I suppose but I worry about the repair costs down the road for such fancy computerized electronics. Makes me doubt I’ll run this car 20 years like the last one.

Marnet


#15

Regular preventive maintenance is the key.

Your Uplander still has the battery saver system right?

After twenty seconds everything shuts down anyway.


#16

You made me wonder about this. I just took my car through the carwash. When the sensor turned on the headlights (engine idling), the dashlights did indeed come on. During daylight, just the parking lights are on which I guess serve as DRL, and the dashlights are off. The sensor seems to operate as an automatic headlight switch as the tailights also come on. If I turn the headlights off manually when the sensor thinks they should be on, a warning message appears on the dashboard which says “Headlights Recommended”.

I really don’t care for this system. I much prefer a simple switch that you pull out to turn on the headlights and push in to turn them off. I think I know enough to turn on the headlights when it gets dark. This new system with its sensors and relays would probably be expensive to fix if something goes wrong. In fact, if the system malfunctions while I have the Uplander, I’ll put a pair of acetylene lights on the front bumper and light them with a match when illumination is needed.