tenyearguy
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Not once!!!!!
2015 Tahoe Disco lights
- Thread starter Gavenger
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BobbyD
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I have had both Dome light modules replaced twice. still flicking and happens while driving, worst when its colder outside
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brittanytahoe
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I have the same problem. I have seen in other forums that the resolution now is to replace All lights and the computer that control radio, alarm, door locks, etc.
bigmoose
TYF Newbie
Finally driving mine enough at night to pick up a pattern in the flashes. Taking it to the dealer tomorrow. I am getting close to the 36,000 mile limit; so specific direction on an effective repair is appreciated.
Does anyone have the updated PI1268 TSB? Does it say what part numbers are replacements? Is the computer that controls the lights, locks etc on the revised TSB?
Does anyone have the updated PI1268 TSB? Does it say what part numbers are replacements? Is the computer that controls the lights, locks etc on the revised TSB?
bigmoose
TYF Newbie
Very thankful for the wisdom on this web site! Got mine repaired at the dealer this morning, and I think I understand what is happening a little better. Note that some of this is conjecture. (I'm a EE that did spacecraft power systems for 35 years)
My complaint to dealer: Second row "dome" lights random flicker/flash on first startup. Seems to correlate with brake light application. Did not seem to happen during evening/nightiime driving. I told them about PI 1268 right from the beginning.
Dealer acknowledged PI1268 and took action based on it. They replaced Qty(2) light modules in the front center console, part number 23104411.
I got to talk with the tech and see the old modules, but he wouldn't let me take the circuit board out as they had to return warranty parts. My observation was that the 1 inch square circuit board was "smart" as in it likely had a microprocessor on it.
My conjecture: The second and third row lights are slaved off the front modules. The front modules have a microprocessor in them. That microprocessor has a "brownout" feature, that reboots the micro after a power outage, or a glitch. With age ( my Tahoe was bought in 12/2015 and has 32,000 miles on it) a critical component has drifted in value and/or the power line glitches have gotten worse. Under certain conditions the microprocessor is doing an automatic reset and rebooting. The flash is coming from the instant the micro reboots, before it runs through its startup code for the first time to extenguish the light.
I have seen this type of behavior in my regular work, and oftentimes we can solve it with additional filtering on the main power feed. I would propose that if anyone has this problem, and is skilled in small scale electronics that you add a couple of uF to the rails on the input to the microprocessor. To the others, that means add some capacitance to the incoming power supply to the module, as close to the microprocessor as possible. This helps to "stiffen" the rails and lessen transients and hash on the line.
If anyone has the detailed schematic of this lighting sub system, and/or wants to send me a defective module, I will try to add the capacitance, and then show a picture of where to do it. I can't guarantee I won't fry the module.
If you have this problem, make sure your dealer knows about PI1268. The reason for this lengthy reply was that the service guy and the technician came to me and asked my opinion, as an engineer, on why changing the front module would solve a problem further down the chain.
If this fix does not work (changing the 23104411 module) I will post again.
My complaint to dealer: Second row "dome" lights random flicker/flash on first startup. Seems to correlate with brake light application. Did not seem to happen during evening/nightiime driving. I told them about PI 1268 right from the beginning.
Dealer acknowledged PI1268 and took action based on it. They replaced Qty(2) light modules in the front center console, part number 23104411.
I got to talk with the tech and see the old modules, but he wouldn't let me take the circuit board out as they had to return warranty parts. My observation was that the 1 inch square circuit board was "smart" as in it likely had a microprocessor on it.
My conjecture: The second and third row lights are slaved off the front modules. The front modules have a microprocessor in them. That microprocessor has a "brownout" feature, that reboots the micro after a power outage, or a glitch. With age ( my Tahoe was bought in 12/2015 and has 32,000 miles on it) a critical component has drifted in value and/or the power line glitches have gotten worse. Under certain conditions the microprocessor is doing an automatic reset and rebooting. The flash is coming from the instant the micro reboots, before it runs through its startup code for the first time to extenguish the light.
I have seen this type of behavior in my regular work, and oftentimes we can solve it with additional filtering on the main power feed. I would propose that if anyone has this problem, and is skilled in small scale electronics that you add a couple of uF to the rails on the input to the microprocessor. To the others, that means add some capacitance to the incoming power supply to the module, as close to the microprocessor as possible. This helps to "stiffen" the rails and lessen transients and hash on the line.
If anyone has the detailed schematic of this lighting sub system, and/or wants to send me a defective module, I will try to add the capacitance, and then show a picture of where to do it. I can't guarantee I won't fry the module.
If you have this problem, make sure your dealer knows about PI1268. The reason for this lengthy reply was that the service guy and the technician came to me and asked my opinion, as an engineer, on why changing the front module would solve a problem further down the chain.
If this fix does not work (changing the 23104411 module) I will post again.
Thanks for all the information in this post. I'm dealing with the issue at 40K miles so no warranty. I tried to open a case with GM and they pretty much said no recall--no chance of us helping out.
Updates I got that may be useful is the PI number has moved to PI1268b and they have updated part numbers for the modules, I will add those when i get back to the house if they are different than the ones in the reply from bigmoose.
I believe I can find the parts for around $35 a piece and now I'm just checking if anybody has instructions for pulling apart the front dome light overhead assembly? I think that is what needs to be replaced. If anybody has any pictures that would be great. ~Dan
Updates I got that may be useful is the PI number has moved to PI1268b and they have updated part numbers for the modules, I will add those when i get back to the house if they are different than the ones in the reply from bigmoose.
I believe I can find the parts for around $35 a piece and now I'm just checking if anybody has instructions for pulling apart the front dome light overhead assembly? I think that is what needs to be replaced. If anybody has any pictures that would be great. ~Dan
Get it to the dealer before you run out of warranty....... ;-)
04ctd
Full Access Member
well, a change in PN would indicate that they added the capacitance BigMoose suggested, and it should be fixed now.
are the 2016's having this problem, this post with the updated PN is Nov 16, which means the old PN would have been used in early 2016 builds....ouch!
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