PWM Sweep Noise when in Auto or 4WD

[tbully]

I haven't fixed mine yet. I plan to do what hosseface did and just insulate it for now. My dealer looked for TCBs for me and couldn't find anything. I haven't found a good insulation material in my garage so not sure what I'm going to use yet. Very annoying problem, though, and sad that we're jamming towels in to the dash of our ~70K brand new trucks.

Curious. TCM used to stand for Throttle Control Module. But I've read that this is coming from a "Transfer-case Control Module". Which is it?

 

[revengejr]

Thanks for the suggestions and replies. I spoke with the service manager at the dealership today. He suspects, as do I, that if he continues testing this on other Tahoe's (3 so far), the results will be the same. The first course of action they are going to do it contact GM directly to see if they have a fix. I did mention the TCM to them but he didn't take much notice. Since I can now prove the problem to them, I think they are taking this a bit more seriously. He said that if GM can't/won't do anything, then he will consider the idea of insulating the noise causing component and run it by GM to find a safe way to do it. I will keep you all posted on what happens...and yes, this is pathetic to have to do this on a brand-spanking-new $70k truck. Ruined the new car experience for us and quite frankly makes me not want to get another Chevy again, ever. Let's see how they deal with this....

**Also worth noting: on our truck, the switch only has 3 settings: 2-high, Auto, 4-high, in that order. Since it controls the drive-train, I suspect Transfer Case Module would be the correct name for the component.