Headlamp LED "eyebrows" suddenly flickering?

I've had my FFE for about 11 months now and often use the LED "eyebrows" during the day as "daytime running lights". I always notice their glow against the garage wall when I pull in at work... a soft steady white glow.

This morning, after my drive to work, I noticed that the glow against the wall seemed to be slightly "flickering" instead of steady. So, I got out of the car and looked directly into the banks of the LEDs. Sure enough, the LEDs were subtly changing brightness (not going completely out, just changing in intensity) several times per second, with more or less random timing.

Has anyone else ever noticed this? I've often admired the LED eyebrows on my FFE and have never noticed them flickering like this. I'm sure this is the first time I've seen it... I am usually pretty sensitive to issues like this.

Have my headlamp units suddenly gone defective? The only recent change (that could possibly be related) that I can think of is that the temperature dropped dramatically in my area in the last couple days... from daytime highs in the 60s to now in the 40s.

Btw, I have not had the side-marker recall performed yet, so my headlamp units are still "factory new".

Yes, I noticed my doing the same thing last week, but I haven't checked it since. I'll try to remember to check this evening. I've had my FFE for 7mo, and I have received the side marker recall.

Funny you should mention that...I had the same observation last night.
Usually I wouldn't have noticed, but I've been looking at the 12V battery lately with a conincidently named "Wattsup" meter attached to the Accessory port in the center console. Typically, when the car is started, the charge voltage on the 12V battery goes to about 14.35V on my car. After awhile and before I get to work in the morning, the voltage drops to 13.3V. I figure the car detects a full charge and goes to "float" mode.

On the way home from work last night, I noticed that the 14.35V charge remained the whole way home....or at least when I got home. When I pulled into the garage, I noticed that it was above 14V. I thought it was probably because of the headlights. So, leaving the car on, I turned the headlights on so just the LED lights were on....I didn't write anything down, but if memory serves, the voltage dropped back down to around 13.3V, or the float voltage.

I think I turned the headlights on and off watching the battery voltage change. Then when I turned the car off with the headlights on led-only mode, I noticed that the eyebrows flickered for a little bit. My guess was that as the voltage transitioned, the regulator to the LEDs was probably having some difficulty adjusting to the changing input voltage.

I don't know why you would have seen it for a sustained amount of time, but if it repeats itself, measure the battery voltage and see what is going on. I'll do the same thing tonight and see if I can reproduce it. Hopefully you see some correlation between what I did and what you did to get this to happen.

I tried to reproduce what I saw yesterday and was unable. I'll keep an "eye" on it.

Just a +1

I noticed this the other day as well. My car is 6-days old.
In my situation it was after I parked in my garage (roughly 45°F) after coming home from work. Car was "off"
I toggled the lights off and back on, and haven't seen the flickering since.

Hmm, it seems the flickering only occurs when the car is turned on and is also in ready-to-drive mode.

Before leaving work today, I sat there in the car, with it still turned off, parked facing the wall and turned on just the eyebrow LEDs. They came on steady. I carefully observed the glow against the wall for a while and also got out and looked at the LEDs. Definitely no flickering.

When I turned the car on to get ready to drive way (so my foot was on the brake the car transitioned into RTD mode), the glow in front of the car (against the wall) started flickering. When the turned the car off to check, the glow went steady again. I repeated this a few times to verify. Definitely flickering starts when the car is made RTD, and stops when the car is turned back off.

Later at home, I tried the same thing in my garage, but this time without holding the brake, and glow remained steady with the car on or off. Hmm. So, I again tried turning the car on with my foot on the brake (to become RTD) and, sure enough, the flickering only appeared then, when the car was made RTD.

So, can anyone else corroborate this? That the eyebrows flicker when the car is on, but only when RTD, and don't flicker otherwise?

Does everyone's FFE do this? Have I just not noticed it before?

Mine has had the "flickering" eyebrows since I bought the car 10 months ago. Just thought it was normal.
Did check and it is solid prior to going to RTD. Good observation WattsUp.

I have a 2014 built 9/2013 and I have not noticed any flickering of the LEDs at all. What I do notice is that the HID headlight bulbs almost seem a little loose to me. When I hit a bump or lane changing hitting the "bots dots" I can sometimes see what looks like a flickering or movement of the bulb if that's what it's called in the headlight pattern on the road.

Astrand1 said:

I have a 2014 built 9/2013 and I have not noticed any flickering of the LEDs at all.

Click to expand...

Apparently the flickering only occurs in RTD mode and is easiest with the HID headlamps off, just the eyebrows on, and pulled up close to a light-colored wall (in a dark-ish place, like a garage).

The flicker may also be more apparent if you observe the glow on the wall slightly off-center, using your peripheral vision.

WattsUp said:

Astrand1 said:

I have a 2014 built 9/2013 and I have not noticed any flickering of the LEDs at all.

Click to expand...

Apparently the flickering only occurs in RTD mode and is easiest with the HID headlamps off, just the eyebrows on, and pulled up close to a light-colored wall (in a dark-ish place, like a garage).

The flicker may also be more apparent if you observe the glow on the wall slightly off-center, using your peripheral vision.

Click to expand...

Yep. Read the earlier posts on when how etc. I've tried it about 4 times and can't reproduce it as yet.

Does this happen in the summer too? Today is the first day here that has gotten down below freezing and this is the only time I have noticed it.

hybridbear said:

Does this happen in the summer too? Today is the first day here that has gotten down below freezing and this is the only time I have noticed it.

Click to expand...

You've probably just only noticed it. It happens all the time to me. I haven't seen a difference with regards to temperature or season.

As mentioned earlier in this thread, the eyebrows only seem to flicker when the car is turned on (that is, in "ready-to-drive" mode versus "accessory" mode). As soon as you turn the car back off (back to just "accessory" mode) and the eyebrows are on, they immediately become steady again.

I guess the difference is, the eyebrows are steady when running off "pure" 12V battery power, but flickering when running off the voltage converter from the HV battery (which charges the 12V battery when the car is on). That's all I can surmise. There must be something "unsteady" about the power supplied by the converter.

That all said, very occasionally I find the eyebrows not flickering when the car is in RTD mode. For example, sometimes when I pull up the wall in the garage at work or home, with the car still on, the glow against the wall is steady (perhaps the 12V battery isn't always being charged while the car is on?). But, more often than not, the glow is flickering until I turn off the car and return to accessory mode, as described above.

Interesting. Now the temp is in the upper 30s and they are not flickering like this morning. This morning it was in the 20s and the car was giving the "it's cold outside" dash message. I'll continue to monitor it going forward.

At this point we don't have enough range to get home so our next stop will be at Goodwill to charge.

I did some experimenting last night when I got home. The car had been out all day with temps in the 30s. I pulled in facing the wall in the garage to test this.

I was in D and the lights didn't flicker.
I shifted to N and they flickered a little.
I shifted to P and they stopped flickering.
I shifted to R and they flickered a lot.
I shifted back to P and they began to flicker less.
Back to R and the flickering increased.
To N and the flickering decreased.
To D and it stopped.
Back to R and it began again.
Back to D and it stopped.
To P and it decreased but didn't stop.

Very odd...

hybridbear said:

I did some experimenting last night when I got home. The car had been out all day with temps in the 30s. I pulled in facing the wall in the garage to test this.

Click to expand...

What about when you turn the car off and enter "accessory" mode. Did they go steady?