ak2007r6

iTrader: (1)

I recently replaced all the bulbs in the front and rear of my truck with some LED's. While they look great I now have the super fast blinking when I use my turn signals. I have read that some use resistors inline to each bulb to fix the problem but I was hoping to find an easier solution. During my google searching expedition for an answer I found this.


http://www.gmupfitter.com/publicat/b...etin_81_D3.pdf


If I read this correctly it appears I can have a dealer change something in the BCM to tell it that it that everything is ok and the bulbs will blink normal.


Anyone have any more info on this? Is this an option or something I can change in HP Tuners by chance or will this take a Tech 2 or something else to correct the issue?


Or am I way off base and need to buy a bunch of resisters??

JFOLM

iTrader: (8)

My buddy is wanting to do the same and mentioned having a tech do something to the bcm so I am in for an answer as well.

rjwz28

Sounds right to me. The LEDs draw so little power that the BCM believes the bulbs to be out, so it does the fast flash. Since chassis cabs typically use small aftermarket lights for brakes and signals (which are often LEDs these days), GM has seen fit to provide guidance for dealers to allow them to prevent rapid blinking from the signal system in such installations. It looks like they have enabled the dealers to reprogram the BCM to compensate for the LEDs. I would call your dealer's service department (I know, huge PITA because they are usually idiots, but at least you have the bulletin) for further guidance.

rjwz28

I don't know if that will eliminate the fast blink though, unless they can do the same for the front signals. These may not be able to be adjusted, as the reason for the whole bulletin is chassis cab trucks, which end up with LEDs only in the rear.

ak2007r6

iTrader: (1)

Worth a shot. From what I read it just tells the BCM to ignore the "bulb burnt" or "missing" signal it gets so hoping that covers the whole truck and not just the rear lights.

I know a couple of techs at the local GMC Dealer, will see what they can do for me. Will let everyone know what happens when I do.

rjwz28

Sounds good. That would be ideal if it was just a blanket solution for any signal from a blinker being out.

ak2007r6

iTrader: (1)

Will I have to have a stock tune on the truck for them to make whatever changes they have to make?

That could be a problem....

JFOLM

iTrader: (8)

I don't see how adjusting the bcm would be affected by your ECM tune but I am not a pro.

Elrey7698

U need some 50w 6ohm resistors..u can find them online for around $5 a pair..make sure they dont make any contact with plastic parts because they run hot..

ak2007r6

iTrader: (1)

Gong to try the method I posted above first. I know a tech at the local GMC dealership that said it would be super easy to do.

If that doesn't fix it I will do the resistors. But I think if we can tell the BCM to ignore the burnt or missing bulb signal and to just blink a steady rate it will be tons easier than soldering in a bunch of resistors