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Short, Happy Life of GM LEDs

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BobGroh
User Rank
Platinum
RE: Short life of GM LEDs
BobGroh   11/1/2011 10:56:58 AM
Couple of comments to throw out here. 

C#1: You should definitely take this up the organizational chart at GM - starting with the local dealer (as you did) is a good start but you usually (in my experience, anyways) can not stop there. I would speak with someone in the dealer's management, not about the light problem, but to get the name, telephone numbers, mail address and email address of the district management. Then contact the district management and layout your case just as you have here with all the details.  No satisfaction there? Go up one more level. Letters, emails, phone calls - keep pounding at it.

C#2:  After you install the new replacement module, tear apart the old one and poke around and see if you can see what the problem is.  Ditto with any other modules you can find to play with.

C#3:  Do a web search for similar complaints.  You'll probably find many.  Integrate all that into your search. At least you can find some grim satisfaction in pursuing this!

I just completed a somewhat similar search for problems with a Maytag dishwasher - a fairly consistent and high failure rate in the controller module. Unfortunately Maytag has been swallowed up by Whirlpool and no one seems to care anymore but, from a web search, we did discern the basic problem (i.e. corrosion of the contacts on the connector) and fixed the problem with a new controller (next time we'll clean the contacts!). 

On another more automotive related case (more than a few years ago), we had purchased a new car and we went back to the dealer to buy a few standard spare parts 'just in case' (e.g. points (so you know this was a long time ago!!)). Well, the parts manager said 'We don't have any and we can't get any'.  So we got mad, marched down to the manager's office and said 'we need the name and phone number of the district manager'.  Then we called the district manager and complained mightly. A week later, we got a letter from the district manager saying we should go back to the dealer - if they still wouldn't order the parts, go to the dealer's manager and ask him to call so and so in the district office. Well, when we trotted back to the dealer and the parts guy again said no parts and so we trotted down to the managers office and laid the letter on his desk.  He excused him self and came back 5 minutes later saying 'The parts are on order - they will be here in 5 days'.

Now your part is 5 years old and probably you won't get any joy in taking it to the 'man' but, hey, at least you can say you tried!

 

davegroe
User Rank
Silver
RE: Short life of GM LEDs
davegroe   11/2/2011 11:09:21 AM
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Overall I have been very happy with my GM trucks (1989 Chevy 1500, replaced with a 2002 Avalanche). The one problem I have had with the 2002 Avalanche is that the interior lights burn out. Radio, trip computer, power window indicators (drivers front, passenger front, passenger rear). All of these use the small grain of wheat bulbs, and are soldered to circuit cards. I spent about 6 hours recently replacing all of the burned out ones. The bulbs are very inexpensive, but require labor to replace them. The ones in the power window switches are difficult. The back side of the CCA is covered by the enclosure they are in. I used side cutters to actually cut/break the light bulb so that I could unsolder from the component side to replace. searching the web it is obvious that these bulbs burn out quite frequently. GMs solution is to replace the radio, switch assy, etc.

Dangela
User Rank
Bronze
Not a GM fan.
Dangela   11/2/2011 9:25:22 AM
GM makes crap. They always have and always will. Obama should have let them go under.

philipp10
User Rank
Gold
Expensive tail light
philipp10   11/2/2011 9:30:13 AM
Sorry to say it but this is typical GM and par for the course.  I got badly burned by that company back in 1988 and never owned another GM product again.  When a company is going to install a tail light that cost $223 to replace, it better be sure it's never going to need replacing.

To be fair though, I had a run in with Toyota last year that made me think I may look elsewhere for my next vehicle.

LloydP
User Rank
Gold
Center taillight failure
LloydP   11/2/2011 10:27:38 AM
A center-mount taillight is a federal safety requirement. All cars and light trucks have been required to have them since the mid 1980's. They were required to give drivers advance warning of brake application one or more vehicles ahead, thus reducing the liklihood of tail-end crashes.

Failure of this indicator is, in my opinion, safety related. All such failures should be reprted to NHTSA. Without customer complaints, they cannot react. Check their web site for similar complaints. That is another way to apply pressure to get your faulty light replaced.

MIROX
User Rank
Platinum
Re: Center taillight failure
MIROX   11/3/2011 2:32:53 AM
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Definitely FILE a complaint with NHTSA here is the link:

https://www-odi.nhtsa.dot.gov/ivoq/

Requirements:

1.) You must be the vehicle owner, complaints from 3rd party will be disregarded, but you not need to be original owner, just current owner, no time or mileage  limit

2.) YOU MUST have the VIN, Date of Occurence and vehicle odo mileage if any is missing it it not a valid complaint

3.) There is no limit (time or miles) on safety issues, even out of OEM Warranty complaints are valid, and MFG will have to recall or reimburse owners if there is recognizible safety defect trend.

However there also is no $ limit on how much OEM can charge for any replacement item, if they choose to charge you $1,000 for a bulb they can and in most cases will get away with t if people do not file direct complaints.

 

NHTSA does not have personall to monitor web or police the OEMs

 

 

 

 

vandamme
User Rank
Silver
C'mon, you're engineers!
vandamme   11/2/2011 11:39:25 AM
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Take it apart and do a post mortem on it. Did a resistor burn out? They probably aren't using a fancy current regulator...or THAT would burn out. Is the circuit board cracked from temperature cycling? Is one LED in a string bad? For 200 bucks, it's worth fixing it. To make fools of GM, definitely!

shjacks45
User Rank
Bronze
Dead Leds
shjacks45   11/21/2011 5:09:08 AM
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Local transit authority tested some tail lights and brake lights. Several older designs used Red LEDs ~.7 V at current and enough of them to make 12V and a small value resistor. If one LED fails open then no light. if one fails short than the higher current eventually causes future faiures. The best ones had many parallel LED strings so that the Brake lights still had adequate light to meet State standards even though you could see multiple LEDs had failed. Failure cause? Vibration, contamination, heat, voltage spikes (40 V from 12 V nominal system), light (LEDs are photosensitive, damaged by radiation)?

LED damage by heat can be lessened by pulsing them. Commercial vehicles, where pulsing was tried as a safety measure, pulse when brake pedal applied, but stopped use air e-brake. Auto requires keeping foot on break pedal at stop light.

Having designed with Laser diode (LEDs): light emission declines over time as carrier availability declines, partly due to temperature and in part by photons; laser diodes often had an included photodiode to provide feedback; light emission increases as an exponent of current (some ordinary LEDs will 'Lase', emit coherent radiation, at higher currents) hence low duty cycle pulsed LEDs are more efficient and generate less damaging heat; also deterioration of phosphor in white LEDs;  .

Reason for design emphasis is that most contemporary LED lighting uses a series string of white LEDs and a (direct current) current limited switching regulator.in other words designs are more sophisticated and more failure prone.

There are more reasonably priced third party replacements that are less expensive than the time to do diagnostics.

 

shjacks45
User Rank
Bronze
Dead Leds
shjacks45   11/21/2011 5:09:29 AM
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Local transit authority tested some tail lights and brake lights. Several older designs used Red LEDs ~.7 V at current and enough of them to make 12V and a small value resistor. If one LED fails open then no light. if one fails short than the higher current eventually causes future faiures. The best ones had many parallel LED strings so that the Brake lights still had adequate light to meet State standards even though you could see multiple LEDs had failed. Failure cause? Vibration, contamination, heat, voltage spikes (40 V from 12 V nominal system), light (LEDs are photosensitive, damaged by radiation)?

LED damage by heat can be lessened by pulsing them. Commercial vehicles, where pulsing was tried as a safety measure, pulse when brake pedal applied, but stopped use air e-brake. Auto requires keeping foot on break pedal at stop light.

Having designed with Laser diode (LEDs): light emission declines over time as carrier availability declines, partly due to temperature and in part by photons; laser diodes often had an included photodiode to provide feedback; light emission increases as an exponent of current (some ordinary LEDs will 'Lase', emit coherent radiation, at higher currents) hence low duty cycle pulsed LEDs are more efficient and generate less damaging heat; also deterioration of phosphor in white LEDs;  .

Reason for design emphasis is that most contemporary LED lighting uses a series string of white LEDs and a (direct current) current limited switching regulator.in other words designs are more sophisticated and more failure prone.

There are more reasonably priced third party replacements that are less expensive than the time to do diagnostics.

 

cwins
User Rank
Silver
Why is GM still in business?
cwins   11/2/2011 12:02:40 PM
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The people voted GM out of business for a reason. Corvair, Olds diesel, a V6 that required motor mount removal for new spark plugs, the list is almost endless. It requires a lot of hard work to design and manufacture a serviceable qualtiy product. Who over rode the decision of the marketplace ?

Analog Bill
User Rank
Gold
Me, too!
Analog Bill   11/2/2011 5:34:34 PM
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Although my first car was a '55 Chevy and I loved it (they were so simple then) my first encounter with GM and their "we don't give a damn once we've sold it" attitude was with my 67 Pontiac Sprint (OHC 6-cyl). Ever since delivery, it had zero oil pressure until engine speed reached some 2,000 RPM. The dealer's response, as well as the famed "district office" after several complaints to the dealer, was "it's covered by warranty if it stops running". They couldn't have cared less. It still gripes me when I know they spend far more money on "feel good" public relations ads than they do for some decent engineering. I've never ever considered buying a GM product - and discourage all my friends, too. Companies this big should be allowed to sink of their own weight (and ignorance in GM's case). Sorry for the workers, but Ford and others will take up the slack!  Oh yes, the cost of replacement parts is truly an outrage ... for cars, appliances, virtually anything these days. Curiously, we haven't heard from a single person from GM trying to explain this LED problem ... they're likely under some GM gag order!

creamysbrianna
User Rank
Silver
Re: Me, too!
creamysbrianna   6/25/2012 11:22:46 AM
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@Analog Bill this is around the time that the big three stoped caring about quality and more about profits.  Today they care more about creating the latest and greatest fluff features within the cabins of their vehicles than the quality of the parts that really truely matter.

I had a 1983 Pontiac Grand Prix which ultimatly died due to a rear main seal failure that I unfortuantly didn't notice soon enough to prevent the bearings from failing.

1988 buick skylark: went throught about three alternators and starters, one day the engine died at a light and had it sent to the shop come to find out the timing belt failed.  It was supposed to be changed every 50k I have to admit it lasted least 100k before failure. 

Then there was the 1994 caviler that shot two spark plugs out of the head and caused the threads to break.

After that I never bought another big three car again.  My 2001 honda civic is still running with 205k on it with no major failures with the engine or engine assesories.

The big three understand the "faster and cheaper" part of the "better, faster cheaper" manufacturering mantra but still can not figure out the "better" part still.  There is a reason why Toyota held #1 in sales for almost a year, they make a better quality vehicle than The Big Three.  For those who think Toyota is not made here they have three or four final assembly plants here.  Second the big three likely don't have more than 50-60% ameriacan content in their vehicles so they are gradually becoming imports themselves as well.

woodla
User Rank
Iron
After the Sale Interest
woodla   11/2/2011 7:26:59 PM
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In my experience GM isn't alone in their lack of concern after the sale.  I've had 3 Fords in succession and presently own 2 at the moment.  Last year my 2004 Escape with only 22K miles died on the road with what was found to be a defective fuel pump.  This is a $600. repair and seemed to me an unreasonable failure at such low milage.  I made my way up through Ford in Detroit and their final answer was basically "sorry we're not interested".  In my opinion my wife's Crown Vic with 3 times the milage was the last reliable car Ford made.  

William K.
User Rank
Platinum
Short life of GM leds
William K.   11/2/2011 8:08:47 PM
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I agree that the best thing would be to open the assembly and find the problem, and then repair it. My guess is that it is a poor quality LED that is opening up the series string. Bright red LEDs are widely available from many sources, so getting a replacement will not be that hard. The important part of th task will be setting the current to the correct value. Since efficiency is not the main goal, using dropping resistors would be the best choice.

izzyizzo
User Rank
Iron
Not the only GM LED problem
izzyizzo   11/2/2011 9:11:55 PM
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Until very recently, GM OEM LEDs pulsed at a low enough frequency for some people to see the strobing or ghosting. Though it appeared to affect only a small number of motorists, those who are sensitive to the strobe rate can be distracted such that safe driving becomes difficult. (I can see it, and it makes me crazy.)

Flicker is evident on some other makes, but GM is the worst -- and Cadillac the worst of that bunch.

GM has repeatedly denied "going cheap" on its LED strobe, but proceeded to solve the supposed non-problem somewhere around the 2010-09 model years. But plenty of the old LEDs remain on the road. While it's unfortunate for GM owners that the offending LEDs are going bad, it's good news for those of us whose safe driving is impacted by poor GM quality.

Besides... I'd imagine GM owners are used to design flaws by now. :) 

FinnickyFinn
User Rank
Silver
Re: Not the only GM LED problem
FinnickyFinn   11/19/2011 9:08:22 AM
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I wonder why they strobe the break lights anyway. Why not turn the LEDs on solid. That will make for a much simpler circuit and less chance to break. My guess is that in this case it is not the LEDs that broke, but the electronics packaged into the unit. Still, should have lasted much longer than it did.

tekochip
User Rank
Platinum
Re: Not the only GM LED problem
tekochip   6/25/2012 11:45:14 AM
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That's a darn good question Finnicky. The human eye has quite a bit of persistence, meaning that when we see a bright light for only just a moment we perceive the light for a little bit longer than that. This, of course is the way TVs and movies work by showing an image for only a fraction of a second and then displaying the next image for a fraction of a second. To our eyes the image has been on constantly. Back to the brake lights; if they were on solid the LEDs would have to be run at a lower current and lower brightness to not exceed the maximum average power dissipation, but if the LEDs are strobed a much higher current and brightness can be used and the human eye will perceive a higher brightness than if the LEDs were on solid.


sesterza
User Rank
Iron
how long the LED lived?
sesterza   11/5/2011 6:43:10 PM
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how long the brake light on 2006 Tahoe did work? Five year, maybe 20 kmiles/year, maybe 50 MPH mean speed: it means 2000 hours of car service but only few % of brake light on, can we say 10% duty? sure much less but even 200 hours of brake light life make me crazy!

Alexander Wolfe
User Rank
Blogger
LEDs are supposed to have long lives
Alexander Wolfe   11/16/2011 8:41:55 AM
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This experience is counterintuitive. LEDs are supposed to be long-lived. Is this some kind of over-voltage situation? If you want to hear some interesting stuff about LEDs in tech usage, check out the archive posting of a Design News Radio event I did with LED expert Carol Lenk, How LEDs Are Changing Embedded Design.

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