# DRL only Flicker when engine running- HELP



## easygoin4 (Apr 17, 2019)

First off How do you know if GEN 2 and if 2016.5 model year?
I have 2016 Cruze LS - it has a LED strip in the headlight assembly.
When key on - steady lights.
Car running- the strips on both sides flicker not always and not constant, just on of fast every few seconds.

This car has 32,000 miles on it runs, drives great.
It was in an accident left front, and bumper, grill, left. fender and headlight replaced.

Headlights HI and Low and turn signals are fine...

Any thoughts?
Thanks in advance...


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## Ma v e n (Oct 8, 2018)

There's no such thing as a 2016.5
A Gen1 and a Gen2 2016 will both have a "G" in the 10th digit denoting 2016 model year.

you can tell a Gen2 by the 4th digit in the VIN. It's a "B" on Gen2 and a "P" on gen1


Was the headlamp assembly replaced with a GM part or an aftermarket replacement. I've seen non original lamp assemblies cause weird issues with a vehicles LED lighting.

Also just as likely is that you've got some form of damage remaining causing the issue. Such as a poor connection, or a chafed/pinched wire.


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## easygoin4 (Apr 17, 2019)

Thanks alot for the info.
I have a G=2016, and a B=Gen 2
Now I know..

Do not know if OEM but there is a chevy bowtie on both of them.

When my daughter brings car back home I will be digging into it..
Thanks again


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## ChevyGuy (Dec 13, 2014)

Ma v e n said:


> There's no such thing as a 2016.5


Some people refer to the Gen2 2016 as a 2016.5. 

A quick way to tell is to look at at the Cruze Talk banner. Does the front of the car look more like the blue car (Gen 2) or the red car (Gen 1)?

Unless aftermarket, I think the Gen1 DRL LEDs were always down around the fog lights. (2011-2014 or so, the headlight it self was the DRL - no LEDs). The Gen 2 DRL LEDs are part of the headlight.


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## Ma v e n (Oct 8, 2018)

ChevyGuy said:


> Ma v e n said:
> 
> 
> > There's no such thing as a 2016.5
> ...


I know some people do, especially on this forum. Doesn't change the fact that there is no such thing as a 2016.5 Cruze, and perpetuating the misinformation causes confusion.

If the 4th digit of the VIN on your Cruze is a "B" you've got a Gen2, simple, accurate, doesn't require knowledge of the banner of the site, the ability to see colors, or rely on artwork that may change. ?


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## easygoin4 (Apr 17, 2019)

Now I see the Blue front end - YES just like that- Confirms Gen 2.. THANKS
Does anyone have a wiring diagram on these headlights or DRL, anything.
I think I need to trace the wires from lights back, and or look for a ground.

Thanks Again guys for the help..


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## Ma v e n (Oct 8, 2018)

Ground G101 is attached to inboard side of left frame rail, x110 is the plug at the headlight, x100 is the big 40way connector on frame rail. 
While they have separate wiring and drivers you can see the LEDs share a single power source, which is why one being wonky can affect both.


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## easygoin4 (Apr 17, 2019)

Oh man thanks a million- I will start with this.
I wont have the car back to my home for a week or so, my daughter has it in a different town, but will be all ready..


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## ChevyGuy (Dec 13, 2014)

I'll note that failing LEDs are more likely to flicker under higher voltage - such as when the engine is running. So, while this could be bad connection/vibration, I wouldn't rule out failing LEDs.


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## easygoin4 (Apr 17, 2019)

Thanks I know, but both of them?

Was thinking to day I should check the Alternator to see if working properly and not making them pulse.
Just have to see how to check that at home with volt meter.

Thanks everyone....


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## ChevyGuy (Dec 13, 2014)

easygoin4 said:


> Thanks I know, but both of them?


Question, do they flicker in sync? And, in normal operation, is there ever a time when they operate independently? I know on some cars the DRL is turned off on one side when the turn signal is activated. If they flicker in sync but are able to operate independently, that's a big clue.




easygoin4 said:


> Was thinking to day I should check the Alternator to see if working properly and not making them pulse.
> Just have to see how to check that at home with volt meter.


Keep in mind that the battery acts as the filter. An old battery could cause the electrical system to get noisy. Three years was a good run for a battery in the Gen 1. It wouldn't hurt to inspect and clear the electrical connections around the battery.


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## easygoin4 (Apr 17, 2019)

I wont have the car back to me till Mothers day.
But will check with turn signal on - does the other still flicker.
They both flash about the same.
I know for sure I will check connections and battery, but thought 3 years on battery and the dash showing 14.2 volts while driving should be good.

Thanks alot for giving me more things to think about..


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## ChevyGuy (Dec 13, 2014)

easygoin4 said:


> But will check with turn signal on - does the other still flicker.


Just to clarify, what I'm looking for is if the BCM controls the two DRLs independently, or of they're both connected to the same wire. I don't have a wiring diagram for the Gen2, so I'm shooting in the dark. 

IF the two DRLs are controlled independently, then the flickering is probably coming from the BCM - or something feeding the BCM.

Likewise, if the DRLs are flickering independently or in unison, that offers clues about where the problem is.


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## Ma v e n (Oct 8, 2018)

Each one is independently controlled, because they turn off when that sides turn signal is active, but that use the same power source into the BCM.


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## ChevyGuy (Dec 13, 2014)

Ma v e n said:


> Each one is independently controlled, because they turn off when that sides turn signal is active, but that use the same power source into the BCM.


Ok, so if they're flickering in unison, then it's the BCM or something "upstream". If the flicker is not in unison, then it's likely two independent issues (but may similar to each other). Although, I would check the ground connection. They might have that in common.

I'd monitor the system voltage. I know in my Gen 1, the BCM may turn off the charging system in certain situations. But if that voltage jump gets large, it might be seen as flicker.


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## Carminooch (Mar 23, 2018)

2018 Cruze, 1.6 diesel. 6 speed manual hatchback. Completely stock, down to the bulbs and tires.

While new and still to this day, when the car is idling and it’s dark out, and you go to turn the interior lights on. Or if I am at a light and can see my headlights reflection in the bumper of the car in front of me. They faintly pulse. I wouldn’t go so far as say flicker, because they remain on and never turn on and off without my prompting it. But they pulse whether the vehicle is idling, in motion, doesn’t matter if the radio is on or off. Doesn’t change anything. It just...happens. I guess I’ve gotten used to it.


Sent from my iPhone using Tapatalk


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## easygoin4 (Apr 17, 2019)

thanks for the input guys.
I will try and find the source to the BCM, once i figure out where the BCM is..
Run some tests on the voltage, to see if fluctuating.


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## Ma v e n (Oct 8, 2018)

Left side of dash above dead pedal/park brake. Mounted vertically to the A-pillar


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## Chad20101 (Jul 23, 2019)

ChevyGuy said:


> Just to clarify, what I'm looking for is if the BCM controls the two DRLs independently, or of they're both connected to the same wire. I don't have a wiring diagram for the Gen2, so I'm shooting in the dark.
> 
> IF the two DRLs are controlled independently, then the flickering is probably coming from the BCM - or something feeding the BCM.
> 
> Likewise, if the DRLs are flickering independently or in unison, that offers clues about where the problem is.


I would say check the LED control device, which are built into the headlight assembly.look into the headlight with it on at night from the side look under the projector lens .


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