Headlight Illumination Issues

ember1205 · July 2, 2015

Check the voltage to be sure it's 14+ (indicating that it has the newer settings). If so, then yes - a bulb swap would be the only difference between your truck and the ones that have been updated.

Although - you have the 9012 bulbs. Weren't the 9011 bulbs the ones that were coming in the trucks originally? Or, like most days, am I confused?

mafd2 · July 2, 2015

Yep, another day confused lol. 9012's OEM.

bass mechanic · July 2, 2015

Check the voltage to be sure it's 14+ (indicating that it has the newer settings). If so, then yes - a bulb swap would be the only difference between your truck and the ones that have been updated.

Although - you have the 9012 bulbs. Weren't the 9011 bulbs the ones that were coming in the trucks originally? Or, like most days, am I confused?

did you measure the voltage on yours? i don't think the voltage has increased any. you can only get the voltage the electrical system is currently at and i know they did not increase that.

what i do suspect they did is change the Pulse Width Modulation PWM signal sent from the BCM as the headlight output is pulsed. the reason they might do this is is to change the ON time of the bulbs. incandescent bulbs make light by heating the filament. it is not necessary to send a constant 12 volts to it since it retains heat when not actually turned on (still making light) i think they increased the on time and decreased the off time. (making the bulb brighter) why on earth they decided to take brightness away from the bulb in the first place i cannot comprehend..

the problem is it will still read 12-14.2 volts with the engine running whatever the voltage is at the battery at that time.

so unless you know what the pulse frequency was before the reprogram and after and unless you have a frequency counter or oscilloscope, there is no way to "measure" anything but voltage which has not changed.

only thing i can verify is do i have the same bulbs as the replacements? i think not, but i think the point may be moot because regardless of what bulbs they put in there they simply are not bright enough. ill be doing the HID retrofit shortly anyway.

Jordan18 · July 2, 2015

I just took delivery of my 2015 Denali. I don't know my build date but according to your service bulletin posted here anything built after January or February going forward has the BCM update.

However I think I have the old bulbs. I took a pic just now. Does this mean a simple bulb swap will yield the same result?

Sent from my iPhone using Tapatalk

My build date was March 30th and I had phillips bulbs in before, I honestly wish I had tested the phillips first before just throwing the voslas in right away. BCM flash wasn't required as stated in the TSB after Jan 2015 builds.

bass mechanic · July 2, 2015

My build date was March 30th and I had phillips bulbs in before, I honestly wish I had tested the phillips first before just throwing the voslas in right away. BCM flash wasn't required as stated in the TSB after Jan 2015 builds.

so are you saying the Voslas were no improvement?

Jordan18 · July 2, 2015

so are you saying the Voslas were no improvement?

I just can't compare, and it's decently light out where I live throughout the night in the summer. They seem ok, but on my 08 I had lightforce driving lights on top of some upgraded high beams so it's apples to oranges to compare. I am thinking HIDs just because I feel that's what should be in a projector headlight design.

lrymal · July 2, 2015

did you measure the voltage on yours? i don't think the voltage has increased any. you can only get the voltage the electrical system is currently at and i know they did not increase that.....

The BCM update/reflash caused voltage to go from about 12 volts, to about 14, as measured. That made a significant difference even with the older 2012 bulbs. The bulbs in the bulletins are VOSLAs with a 28432 stock number and 12 volt @ 55 watt rating labeling. There are photos of this bulb with the labeling several messages back in this message thread.

The 2 volt voltage increase, as measured, caused a significant brightness increase on the older bulbs, and brought up the illumination enough that even lateral illumination was helped.

Go back about three months in the messages....

bass mechanic · July 2, 2015

The BCM update/reflash caused voltage to go from about 12 volts, to about 14, as measured. That made a significant difference even with the older 2012 bulbs. The bulbs in the bulletins are VOSLAs with a 28432 stock number and 12 volt @ 55 watt rating labeling. There are photos of this bulb with the labeling several messages back in this message thread.

The 2 volt voltage increase, as measured, caused a significant brightness increase on the older bulbs, and brought up the illumination enough that even lateral illumination was helped.

Go back about three months in the messages....

i am sure this is correct, i just placed my order with TRS and fast headlights for the brackets and ill be pulling all the OE crap out of my headlights and installing something worthy of a 60,000 truck shortly. so the point is moot now anyway. but thanks for the info..

GM if your reading any of these threads pull your heads out of your asses!

Panik · July 4, 2015

I just can't compare, and it's decently light out where I live throughout the night in the summer. They seem ok, but on my 08 I had lightforce driving lights on top of some upgraded high beams so it's apples to oranges to compare. I am thinking HIDs just because I feel that's what should be in a projector headlight design.

I think I may have asked for a comparison and also said that I would post a comparison once my dealer did the upgrade, but to be honest that was a good while ago and I haven't really followed the thread since the merge.

I just got around to swapping out my Volsa's to see if the 9011's made even more of an improvement and I think it does make a noticeable difference after the BCM flash. In the pic below the driver's side is a 65w 9011 and the passenger side is a 55w Volsa. To me there is moderate improvement in the amount of light present in the pattern on the left, YMMV.

Unfortunately, I can't really comment on color differences due to the fact that my garage door is dark beige. I also can't comment on any improvments under actual driving situations because it got light too quickly this morning. (Well, that and my stupid dealer forgot to return my other 9011 when they did the upgrade)

Anyways, If someone has already posted a side by side comparison let me know and I will delete the post.

Edited July 4, 2015 by Panik

WLC · July 4, 2015

9011's are 65 watts.

Panik · July 4, 2015

9011's are 65 watts.

LOL true - that's what I get for getting up at 3 in the morning. **Edited my post above to reflect the correction.

Payton34 · July 5, 2015

I drove mine for a week with the updated bulbs and refresh and they really were not much improvement from the driver perspective especially in rain. From the outside looking at the truck the headlights look much brighter whiter but thats about it. I went back to HID may try the GTR LED replacement bulb eventually.

ember1205 · July 5, 2015

I drove mine for a week with the updated bulbs and refresh and they really were not much improvement from the driver perspective especially in rain. From the outside looking at the truck the headlights look much brighter whiter but thats about it. I went back to HID may try the GTR LED replacement bulb eventually.

I don't believe you'd see any improvement at all if you're used to driving with the HID lights, but there is a pretty noticeable difference compared to the lower voltage and stock bulbs.

What are you running for HIDs? What sort of issues have you had (if any), and are they direct fit replacement? Do the HID conversion kits give you better side lighting? That's my biggest gripe with the stock setup - I live in a rural area and can't see when turning street-to-street because there are no street lights. There are plenty of critters, however! Deer and bear are somewhat common in my area with the occasional fox, coyote, or similar.

Payton34 · July 5, 2015

I have the morimoto sierra kit and i have had tipical issues of one light occasionally not coming on and the relay went bad wich made the headlights stay on. Side vision isnt much better. The stock projector design is junk. I have Rigid dot fog lights which give a food wide very bright white light.

Ranch55 · July 12, 2015

Posted 05 March 2015 - 07:08 PM

These are the actual Vosla bulbs and AC Delco / GM Part numbers installed in my truck today at my service department.

We had a big arctic front blow through here last night and everything cleared out today. Big blue sky, but windy and cold as ****. So, tonight I should be able to check the upgrade out and be able to take my comparison photo with the TSB update ........