2020 Equinox Higher Pitched Hum while Auto-Stopped

[kevinc]

I've been trying to figure out why my 2020 Equinox has a higher-pitched hum while stopped at 0 RPM at 0 MPH while auto-stopped. It seems to possibly be climate control/fan related. Yesterday, I took a video of this occurring. Below is a Google Photos link of it since video files are too large for this forum. You'll have to turn the sound up louder to hear what I'm walked about. Has anyone had this occur while auto-stopped?
Google photos link with video:

New video · Tuesday, Feb 10 🎬

Tap to view!

photos.app.goo.gl

 

[ricklack]

The hum still seemed to be there when you first let your foot off the brake, although it is quickly hidden by road noise. Maybe I'm just hearing things? Has the battery ever been replaced? All sorts of gremlins seem to appear when the battery is getting near time to replace.

 

[kevinc]

The hum still seemed to be there when you first let your foot off the brake, although it is quickly hidden by road noise. Maybe I'm just hearing things? Has the battery ever been replaced? All sorts of gremlins seem to appear when the battery is getting near time to replace.

That's a good thought. I've never changed the battery. It's a "freak battery" that's six years old. It doesn't make that hum during driving or coasting.

 

[PoManNox]

Welcome. Assuming this poor 2020 has endured auto stop/start cycles it's whole life, the first thing I would do is eliminate that with one of the ~$12 hood latch bypass harnesses that are talked about a bunch here.

In terms of the noise, does it still exist if you turn off all auto and HVAC systems?

 

[2025 Red Equinox]

I've been trying to figure out why my 2020 Equinox has a higher-pitched hum while stopped at 0 RPM at 0 MPH while auto-stopped. It seems to possibly be climate control/fan related. Yesterday, I took a video of this occurring. Below is a Google Photos link of it since video files are too large for this forum. You'll have to turn the sound up louder to hear what I'm walked about. Has anyone had this occur while auto-stopped?
Google photos link with video:

New video · Tuesday, Feb 10 🎬

Tap to view!

photos.app.goo.gl

On GM ICE vehicles with the stop-start system, the automatic transmission has an electric pump that remains running (with the engine off) to keep the transmission fluid circuits primed.

This MAY be the hum noise that you hear.

 

[kevinc]

Welcome. Assuming this poor 2020 has endured auto stop/start cycles it's whole life, the first thing I would do is eliminate that with one of the ~$12 hood latch bypass harnesses that are talked about a bunch here.

In terms of the noise, does it still exist if you turn off all auto and HVAC systems?

I'll definitely look into that. I've never heard of that. Thanks for the knowledge!

 

[kevinc]

On GM ICE vehicles with the stop-start system, the automatic transmission has an electric pump that remains running (with the engine off) to keep the transmission fluid circuits primed.

This MAY be the hum noise that you hear.

That makes sense. Something I didn't describe in my original post: I had a Jasper remanufactured transmission installed 10k miles ago but I can't remember if the noise started after the install or before.

 

[PoManNox]

On GM ICE vehicles with the stop-start system, the automatic transmission has an electric pump that remains running (with the engine off) to keep the transmission fluid circuits primed.

This MAY be the hum noise that you hear.

I was under the impression that it was more of a pressurized fluid reservoir that was spring/solenoid activated, but you may be right in that it's a motorized unit.

Sorry to say it to the OP, but as soon as I heard Jasper. I gasped a bit. Yikes..

 

[kevinc]

I was under the impression that it was more of a pressurized fluid reservoir that was spring/solenoid activated, but you may be right in that it's a motorized unit.

Sorry to say it to the OP, but as soon as I heard Jasper. I gasped a bit. Yikes..

I didn't know any better at the time. They gave me an option to rebuild for significantly cheaper but I have heard these Equinox transmissions are a "one-and-done". I agreed to the Jasper trans because of the warranty. If it is this electric pump issue, hopefully it's a covered item. I guess I'll have to bring it in.

 

[PoManNox]

I didn't know any better at the time. They gave me an option to rebuild for significantly cheaper but I have heard these Equinox transmissions are a "one-and-done". I agreed to the Jasper trans because of the warranty. If it is this electric pump issue, hopefully it's a covered item. I guess I'll have to bring it in.

If there's no malfunction codes present and it's not effecting driveability, they're most likely not going to do anything.

We all live and learn. A good on-site rebuilt is almost always going to be a better option than a reman'd unit these days because you never know the "quality" of the remanufactured unit.