Robert1955
New member
I have done some looking and thought I could save some time asking here. Does anyone have any technical information on how the AWD system works/operates?
AWD System design/operation question
- Thread starter Robert1955
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In the few years I've poked around and researched the 2018 to current AWD system, I have not come across any tech info on it. I can tell you basic info on the system components and how they work.
Starting at the transfer case (or power transfer unit) up front, this is connected between the front right CV shaft and the transmission. It has an electrically actuated disconnect on it. When you are not in AWD mode, the t-case is 'disconnected' and does not send power to the propeller shaft. The transfer case is easily serviceable. I used Valvoline full synthetic 75w90 in mine with I did it's first drain/fill at ~36K miles.
The propeller shaft / drive shaft connects the T-case to the rear carrier assembly. The rear carrier contains the torque tube, rear differential and the electronically actuated wet clutch that sends power to the rear diff and wheels when front wheel spin is detected. No power will be sent to the rear wheels at speeds of around ~20mph or more. This AWD system is more to get you moving and keep you moving. It is not a fancy torque vectoring system like what you would find on a Subaru, etc. The rear diff is also easily serviceable. I used Valvoline synthetic 75w90 in it also on mine. The clutch housing also has it's own fluid reservoir that uses Pentosin 11s. I have not changed the clutch fluid in mine. It is also easily serviceable.
The cool thing about the AWD system on these vehicles is, it's basically fully disconnected when not in AWD mode, so there's no real drag and fuel economy loss from it. When not in AWD, you can grab and freewheel spin the propeller shaft to verify this.
Starting at the transfer case (or power transfer unit) up front, this is connected between the front right CV shaft and the transmission. It has an electrically actuated disconnect on it. When you are not in AWD mode, the t-case is 'disconnected' and does not send power to the propeller shaft. The transfer case is easily serviceable. I used Valvoline full synthetic 75w90 in mine with I did it's first drain/fill at ~36K miles.
The propeller shaft / drive shaft connects the T-case to the rear carrier assembly. The rear carrier contains the torque tube, rear differential and the electronically actuated wet clutch that sends power to the rear diff and wheels when front wheel spin is detected. No power will be sent to the rear wheels at speeds of around ~20mph or more. This AWD system is more to get you moving and keep you moving. It is not a fancy torque vectoring system like what you would find on a Subaru, etc. The rear diff is also easily serviceable. I used Valvoline synthetic 75w90 in it also on mine. The clutch housing also has it's own fluid reservoir that uses Pentosin 11s. I have not changed the clutch fluid in mine. It is also easily serviceable.
The cool thing about the AWD system on these vehicles is, it's basically fully disconnected when not in AWD mode, so there's no real drag and fuel economy loss from it. When not in AWD, you can grab and freewheel spin the propeller shaft to verify this.
Sewtrapped
Member
I appreciate the technical info. but I have a question if anyone can enlighten me. (2026 LT with this regular gear-driven tran). Since I'm getting better mileage when I keep it in AWD mode I opt to just keep it in AWD. Sometimes I'll be driving and FEEL a difference and look at the mode and it will have switched back to FWD. I thought maybe I was hitting the button accidentally when turning off the engine shutoff thing so I religiously kept track of what button I was touching and never did I touch the AWD/FWD button and it continues to randomly switch back to FWD on its own. Is there a reason that it would do this that you're aware of? I'm only barely to my 1st 1000 miles so it's still very new.
2025 Red Equinox
Member
My wife and I bought a new 2025 Equinox RS AWD, and at 3,1xx miles - the AWD system failed. The dealer diagnosed a failed rear drive module, which was on national backorder.
During the 30-40 days we were waiting for the AWD repair part, the FWD / AWD display would randomly switch back and forth (although the AWD system was inoperable).
When the part arrived and was installed, the repair invoice from the dealer stated the technician made eight attempts to program the new module, which failed each time. He was successful on the ninth attempt.
Perhaps you have a failing AWD rear-drive module? There was a trouble code stored when the module failed on our vehilce.
Here is original post with the TSB and trouble code: https://www.chevyequinoxforum.com/threads/service-awd-system-notification-25-rs-awd.6214/#post-29411
That's interesting
Sewtrapped
Member
I know, right? When in fwd my mileage goes down to 18+mpg and switching back to awd for a few days it's back up to 19.5+/-mpg. Most, if not all, my driving is short distances and barely ever on the interstate. Yes, I'm a retired home body. Had the nox since Sept and now in Feb I'm approaching my 1st 1000 miles. But after I decided AWD was cheaper and just leave it there is when I started noticing the change back to fwd. It just did it today but I did turn the drive mode dial to ice/snow after each errand stop because of all the snow here. I wondered if fwd was a setting for ice/snow which is illogical to me. Also makes no sense why I have to manually turn off the traction control instead of that being off would be an ice/snow setting by default.
Sewtrapped
Member
Because in those conditions if you allow one wheel to lock up because it's slipping, the car will slide off in the direction of that locked wheel. I've experienced this twice, the last time in another car I was going uphill on a snow covered skinny road and the right wheels were locking up because they were slipping and the car started sliding off the road to the right. My instinct reaction was to hit the traction control button to turn it off and the wheels started turning and I was able then to regain control. That car had an easier button to hit. This Nox, I'd have to go into a menu on screen before I could even get to that button so I have to think ahead to turn it off. I've looked it up and it makes sense to me now. TCS is for gravel or other similar surfaces.
ABS deals with braking.
Traction Controls helps to prevent wheel spin during acceleration.
Sewtrapped
Member
I fully understand why and when it should work and was designed to do. However, the other day, I was in deeper snow and had to stop but then, still in AWD, I could not move forward or backward until I turned it off.
Here's what I just looked up:
" An exception is if you get stuck in snow or mud (or muddy snow), leaving the traction control system on could work against efforts to power your way out of trouble."
I believe my situations and experiences have been related to that statement and is why I opt to turn it off.
Stay safe!
Here's what I just looked up:
" An exception is if you get stuck in snow or mud (or muddy snow), leaving the traction control system on could work against efforts to power your way out of trouble."
I believe my situations and experiences have been related to that statement and is why I opt to turn it off.
Stay safe!
You turn off the traction control so you can spin the tires a little and rock the car forward and back.
Don't turn off AWD.
We learned this many years ago with the first car we had with traction control.
Sewtrapped
Member
I never turn off AWD as I've said. What I've been saying basically is that I turn off TCS in snow and ice conditions because my car would've slipped right off into the ditch on a winding, very inclined and slick-with-snow-and-ice road while accelerating if I hadn't reached up and turned off the TCS on impulse as the car started sliding sideways.
That's fine, but understand this will put more wear on the transfer case and driveshaft as these will both be spinning any time the vehicle is in motion with AWD mode selected, regardless if it's active or not.
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Sewtrapped
Member
Thanks for that info. I was not aware. I only do that because my gas mileage computer says I'm getting more MPG in awd which seems illogical in my mind.
For sure the opposite of what you'd think! In terms of my wear comment. It's just a theory of mine based on more parts being forced to move. The driveshaft between the t-case and rear carrier is a "one piece" setup, with the carrier bearing assembly (bracket and all), and all the bits to the driveshaft sold as a unit. If the carrier bearing goes, you have to replace the whole thing. I believe all the Equinox's up to 2017 in AWD flavor, had these components spinning at all times and you don't necessarily hear of that as being an issue.
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