Weird 4wd situation

[Realmc1969]

completely stock 2015 sierra 10,000 miles. I put it in auto 4wd (it was raining) and it started making an extremely high pitch almost electrical sound. Does it when accelerating braking and turning. Put it in 2wd and it stops. I then noticed it makes a roaring sound when I accelerate in auto 4wd. I've never noticed the sound before.

[txchevy4ever]

Normal. I've had 3 chevy's since 2000 and all do that in 4WD Auto

[newdude]

Normal:

 

 

Condition/Concern

Some customers may comment on a high pitched whine noise from the vehicle noticed when driving in auto 4wd. The customer may comment that it is an intermittent noise and no noticeable pattern to when it can be heard.

Recommendation/Instructions

The transfer case control module on these vehicles is located next to the accelerator pedal and is not covered by any close out or hush panels.

When the transfer case control module has to move the transfer case actuator motor the higher current passing through the module causes an "electronic buzz or whine" within some of the capacitors in the module that can be heard by some of our customers.

Typically this can only be heard with all accessories and HVAC off and only when actuator movement is required. This does not indicate a concern with the module and should not be replaced to address this concern.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

 

 

[Realmc1969]

Thanks guys now I regret turning my radio down haha. Good to know its not a mechanical issue

[SouthpawHD]

Rule #1, never turn the radio down, ever. Causes too many other "problems" that you never noticed before.

Rule #2, never hand wash the truck, shows you where all the "imperfections" are.

[white1500]

4wd because of rain? lol

[Clocked92]

Yea I don't see the need for 4wd, even Auto, in rain unless its a torrential downpour with water flowing over the road. A vehicle with traction control, stability control and ABS should be able to handle a little rain.

 

I don't use Auto 4wd. If I need 4wd, I put it in 4Hi in mud, wet grass, deep snow, or ice. Once I get moving or out of the mud or snow, I switch to 2wd.

[seansharley]

In Florida when it hasn't rained for a few weeks, then rains, its like all the oil on the roads make it almost as slick as ice. I've had my truck break loose getting on the highway, I can see where someone would use auto 4 under these conditions for safety

 

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[crafferty]

I tested my auto 4WD at lunch today after reading your post and didn't hear any noises. Everything sounded normal from the time i engaged, accelerated, decelerated and switch to 4hi then 2WD.

 

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[Tattooo]

Normal

[amxguy1970]

In Florida when it hasn't rained for a few weeks, then rains, its like all the oil on the roads make it almost as slick as ice. I've had my truck break loose getting on the highway, I can see where someone would use auto 4 under these conditions for safety

 

Sent from my XT1254 using Tapatalk

 

 

Tyler

[BigBadSierra]

I put my 4x4 on allot in the light rain. We are a boarder city so the truck/car traffic is heavy all over the area so there is always allot of oil coming up from the roads.

 

It's worse in light rain so thats when I use it. The back end slides easy on oiled up roads.