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Dimming/flickering Lights

5829BMG

By 5829BMG
in Ask A GM Technician

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5829BMG Enthusiast

5829BMG

Posted
Posted

I have a 09 GMC CC 4x4 bone stock and at night I notice the lights will dim/flicker like a heavy draw on the system. The alt gauge doesnt move. Anybody else have this or what could be done. All the connections are tight and clean.Any ideas??

ColoradoSkiCountry Senior Enthusiast

ColoradoSkiCountry

Posted
Posted

I assume you don't have an HD/2500/3500 truck. On my 07 I had the annoying flicker/dimming of the headlights and other lights from time to time at night while driving. This is a result of the alternator/charging system. Was very noticable to me, however very common according to 2 dealers I took it to and said there is nothing that can be done about it.

 

I have a 09 GMC CC 4x4 bone stock and at night I notice the lights will dim/flicker like a heavy draw on the system. The alt gauge doesnt move. Anybody else have this or what could be done. All the connections are tight and clean.Any ideas??
Nytemare Senior Enthusiast

Nytemare

Posted
Posted

I am 90% sure there is a TSB on this issue.

 

Its something to do with the Digital Auto Voltage Regulator and they can adjust parameters in the ECM to subdue the flicker. Again I am almost sure there is a Re-flash they do.

Z'06 Enthusiast

Z'06

Posted
Posted

OP, do a Google search on the Big 3 mod (4-guage or 0-guage) to upgrade the factory noodle wiring. :dunno: You could also use a 32% overdrive alternator pulley (available from Black Bear).

sgrah230 Enthusiast

sgrah230

Posted
Posted

Mine also does this and I was told by the service department that this was normal...

 

Anyone know for shore about the TSB???

5829BMG Enthusiast

5829BMG

Posted
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Posted

I too would like to know about any TSB's and if there is a reflash for this concern would it be and BCM or ECM flash.

Nytemare Senior Enthusiast

Nytemare

Posted
Posted
I too would like to know about any TSB's and if there is a reflash for this concern would it be and BCM or ECM flash.

Just phone the GM tech line about it.

  • 3 weeks later...
SIRSTEPHEN New Member

SIRSTEPHEN

Posted
Posted
I too would like to know about any TSB's and if there is a reflash for this concern would it be and BCM or ECM flash.

Just phone the GM tech line about it.

 

 

My truck only does it when the headlights have come on automatically. The dash lights will go almost out and flicker every time you press the brake. 2009 silverado 5.3. Dealer also said it was "normal". Gave me a print out document ID: 2170220. Bulletin #02-06-03-008D. You would think for around $30,000 dollars I could have dash lights all the time while driving.

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