Electronic clicking after shutting off truck

[SuperDuper]

I’m fairly certain it is supposed to do it, but in my 2019 Sierra when I shut off my truck and remain sitting in it for about 5 minutes or so I hear a bunch of electronic clicking and whirring coming from the dash, kind of underneath the steering column area. Just curious what it is making the noise or if anyone else has heard it and knows what it might be by chance. 

[Trail Jefe]

I'm curious too. Sounds like an animal is in the dash.

[Bikeman]

Mine does it as well. Considering it normal 

[Schmoe]

If y’all gave the HUD, it’s retracting, or the electronic parking brake is setting, most likely. 

Edited July 7, 2019 by Schmoe

[Booger T]

Mine does it also, it is not the parking brake and I don't have HUD. Not sure what it is but I would say it is normal

[econometrics]

Yep, mine does as well. RST 5.3L with 3,000 miles. 

[JR09country]

Mine to. Definitely not the ebrake.

Sent from my ONEPLUS A6013 using Tapatalk

[Jremm15]

It is the new electronic braking system doing a system check.  It does this after the truck has been shut off.  I worked on it while it was in development.

[JR09country]

It is the new electronic braking system doing a system check.  It does this after the truck has been shut off.  I worked on it while it was in development.

The brakes are fantastic on the truck so good job to you and your team.

 

Sent from my ONEPLUS A6013 using Tapatalk

 

 

 

[AMPRG]

On 7/6/2019 at 6:26 PM, Schmoe said:

If y’all gave the HUD, it’s retracting, or the electronic parking brake is setting, most likely. 

What do you mean "HUD's retracting"? I've never heard about that! 

[HondaHawkGT]

Relay clicking noises mostly. Also, since the truck doesn't have a normal keyed-ignition, the government mandated column lock uses a solenoid that activates after the truck is in park and engine is shut off. That's pretty audible. Another noise is the solenoid that keeps the shifter in park until the brake pedal is pressed. Apparently GM wasn't willing to isolate the relays and solenoids with noise insulation, so they're all pretty audible when the stereo is turned down or off. Maybe someone will peak under the dash and figure out where they are. Or maybe a tech can give us a diagram of where they're located. A DIY sound deadening mod to make them less audible would be nice.

Edited July 9, 2019 by HondaHawkGT

[John Bro]

On 7/6/2019 at 7:30 PM, Jremm15 said:

It is the new electronic braking system doing a system check.  It does this after the truck has been shut off.  I worked on it while it was in development.

Hello!!! I do have a question. I have a 2020 GMC Sierra. But....when I turn off the ignition and sit in the truck for several minutes, the brake pedal is hard when I try to start it up again - as if the vacuum is lost or something. Additionally, my "Trip" and "MPG" average are both 0.0 instead of actual mileage and MPG like I see at times when entering the cab fresh. Lastly, before finding itself, the warning of "Brake System Failure/ 62 MPH Top Speed" flashed very quickly by. I had my dealer search for a code but nothing there.

 

Thoughts? Why all this after sitting dormant in the cab like on my phone or something?

 

And the Brake Warning doesn't always happen. The 0.0 most always does though after waiting in the cab for too long before start.

 

Thoughts?