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Discussion Starter · #1 ·
Took our limited ascent in because it would surge or chug at low speeds going thru our neighborhood. Didn’t happen all the time. Wife drives it most of the time and she would complain about it and I would try to duplicate it and It happens once for me. Felt like a misfire or in between gears kinda thing even though it’s a CVT. Anyways took into the dealership and the ECM needed to be updated as the tech could not duplicate the issue. So if yours is doing that get it in for an update. Hasn’t done it since the update!!
 

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Thanks for the update!

The only significant issue I have with my Ascent is when driving 15-25 mph and it chugs, like it's going to stall!!
I will be visiting the Subaru service center soon.
 

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Took our limited ascent in because it would surge or chug at low speeds going thru our neighborhood. Didn’t happen all the time. Wife drives it most of the time and she would complain about it and I would try to duplicate it and It happens once for me. Felt like a misfire or in between gears kinda thing even though it’s a CVT. Anyways took into the dealership and the ECM needed to be updated as the tech could not duplicate the issue. So if yours is doing that get it in for an update. Hasn’t done it since the update!!
Do you happen to have any info regarding the ECM update? It could be very helpful for the community. Was there a TSB associated with it? If so, what was the TSB number? Thanks.
 

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Thanks for the update!

The only significant issue I have with my Ascent is when driving 15-25 mph and it chugs, like it's going to stall!!
I will be visiting the Subaru service center soon.
My car does that too and I have always thought of it as a "1-2 shift" at low speeds that happens a little too soon (~20mph) that causes the engine to lug a little bit. I'm very curious if the ECM update mentioned in this post has any potential to fix this.

There are at least a couple of threads about this phenomenon. Some call it "lugging", some call it a "stutter" and some call it a "surge". What is completely unclear is if everybody is talking about the same thing. Me thinks not and it's pretty confusing to anybody who comes here looking for an answer. I asked the OP to see if he/she has any more detailed info regarding the update that was performed.
 

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My car does that too and I have always thought of it as a "1-2 shift" at low speeds that happens a little too soon (~20mph) that causes the engine to lug a little bit. I'm very curious if the ECM update mentioned in this post has any potential to fix this.

There are at least a couple of threads about this phenomenon. Some call it "lugging", some call it a "stutter" and some call it a "surge". What is completely unclear is if everybody is talking about the same thing. Me thinks not and it's pretty confusing to anybody who comes here looking for an answer. I asked the OP to see if he/she has any more detailed info regarding the update that was performed.
And you have other Subaru cvt experience. So, you are not new to how the car should perform.

:thumbsup:
 

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Discussion Starter · #7 ·
Thanks for the update!

The only significant issue I have with my Ascent is when driving 15-25 mph and it chugs, like it's going to stall!!
I will be visiting the Subaru service center soon.
My car does that too and I have always thought of it as a "1-2 shift" at low speeds that happens a little too soon (~20mph) that causes the engine to lug a little bit. I'm very curious if the ECM update mentioned in this post has any potential to fix this.

There are at least a couple of threads about this phenomenon. Some call it "lugging", some call it a "stutter" and some call it a "surge". What is completely unclear is if everybody is talking about the same thing. Me thinks not and it's pretty confusing to anybody who comes here looking for an answer. I asked the OP to see if he/she has any more detailed info regarding the update that was performed.
I knew I should have put that info on here. Unfortunately I recycled the paper from Subaru and can’t find it in the bin. My Ascent has just over 7k and the ECM has never been updated. The update was specific to the chug/ surge of the Engine. That much I know. Hope that helps!
 

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I knew I should have put that info on here. Unfortunately I recycled the paper from Subaru and can’t find it in the bin. My Ascent has just over 7k and the ECM has never been updated. The update was specific to the chug/ surge of the Engine. That much I know. Hope that helps!
Awe, bummer. Thanks. I think those details will pop up in your service history on mysubaru.com at some point. It can take 30+ days though...
 

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Thanks for posting E3, ours (Limited, Oct18 build, 3k miles) does that at about 20-25 mph while going up a long hill in our neighborhood. I thought maybe I was just imagining it but my wife mentioned it too. I'm going to ask about this when I take it in for the first oil change, as well as ask for the head unit to be updated so it will stop losing radio presets.

Great forum, esp for such a new vehicle.
 

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Took our limited ascent in because it would surge or chug at low speeds going thru our neighborhood. Didn’t happen all the time. Wife drives it most of the time and she would complain about it and I would try to duplicate it and It happens once for me. Felt like a misfire or in between gears kinda thing even though it’s a CVT. Anyways took into the dealership and the ECM needed to be updated as the tech could not duplicate the issue. So if yours is doing that get it in for an update. Hasn’t done it since the update!!
I'm so glad you posted about this... wasn't sure if it was something to just 'live with' or if they had an update to smooth things out a bit.

A few questions.... don't stress on the answers, others are free to chime in...

What if any change did you notice after the update?

Is the update 'by request' only, like I have to bring it up as an 'issue' or would they do it during any 'heavy' service? (ie. not an express oil change) Sorta like the infotainment, I have to request a warranty service to get that updated. (non-Nav)
 

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Discussion Starter · #11 ·
Took our limited ascent in because it would surge or chug at low speeds going thru our neighborhood. Didn’t happen all the time. Wife drives it most of the time and she would complain about it and I would try to duplicate it and It happens once for me. Felt like a misfire or in between gears kinda thing even though it’s a CVT. Anyways took into the dealership and the ECM needed to be updated as the tech could not duplicate the issue. So if yours is doing that get it in for an update. Hasn’t done it since the update!!
I'm so glad you posted about this... wasn't sure if it was something to just 'live with' or if they had an update to smooth things out a bit.

A few questions.... don't stress on the answers, others are free to chime in...

What if any change did you notice after the update?

Is the update 'by request' only, like I have to bring it up as an 'issue' or would they do it during any 'heavy' service? (ie. not an express oil change) Sorta like the infotainment, I have to request a warranty service to get that updated. (non-Nav)
After the update didn’t notice the chug or surge. My wife hasn’t noticed or complained about it so that’s good LOL. If you want it taken care of now I would schedule a appointment with Subaru and get it taken care and tell them you have heard there is an update and would like it taken care of. And let them no the issue of what you are experiencing. I wasn’t in for an oil they were fixing a trim piece on my console and brought it up to them and they took care of. Just ask to update anything that needs to be done
 

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This is what I saw on STIS:

11-190-19R Technical Service Bulletin
DTC U0122 and Hesitation at Highway Speeds-ECM Reprogramming...
Mar 4, 2019

I don't have an active subscription, so I can't check it out.
 

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Took our limited ascent in because it would surge or chug at low speeds going thru our neighborhood. Didn’t happen all the time. Wife drives it most of the time and she would complain about it and I would try to duplicate it and It happens once for me. Felt like a misfire or in between gears kinda thing even though it’s a CVT. Anyways took into the dealership and the ECM needed to be updated as the tech could not duplicate the issue. So if yours is doing that get it in for an update. Hasn’t done it since the update!!
My issue was similar. When I leave the house in the morning with varying warm ups. 0, to a minute all the way to 10 when the remote start stops. I will accelerate at a constant foot pressure, which I verify with the three gauge screen. The car hunts for the right gear ratio it seems and the RPM surges back and forward. The dealer kept my car over night to recreate this, then went on a road test with me for other issues and said couldn’t replicate. Smh. We didn’t try to replicate it there, YOU were supposed to in the morning, guy. They flashed it anyway and I’m not sure it’s gone but it’s certainly better.
 

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I took mine in at ~8000 miles with a similar complaint. While on a trip, I was going up a very steep hill in Pendleton, Oregon and I could not hold a steady 25 MPH. Test drove with a technician when I got home and couldn't duplicate it, no hills here that are long enough and steep enough. Here's what the service ticket showed: "Customer states uphill surge. Check for any codes in ECM or TCM and found none. Check for bulletins and found none for this concern. Check for ECM updates using flashwrite and found there is an update. Update ECM software."

I don't know if this completely cured it, but it definitely behaves differently going up hill below 30 MPH. It tends to hold the RPM higher and not upshift as early as it used to.
 

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My ECM update was completed a couple of days ago. Overall there is an improvement! I immediately noticed in certain situations when accelerating it doesn't feel like I've gone from "first" gear to "third" gear - skipping second (manual analogy)! The lugging and lurching has definitely subsided but not completely gone away.

With 15K on the odo, my Touring transmission still chirps when going into drive but I haven't noticed the tea-pot whistle as frequently. But with this update and my guess more will follow, my Ascent, actually felt more like my 2009 Subaru Forester XT. It wanted to go and not be held back at low speeds.

Yes, I still have my XT with 175,000 miles original turbo. Rattles shakes and roles but still a blast to drive!

Hopefully others will experience the same results!
 

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Good to hear. I have this issue about 95% of the time, pretty annoying . It really lurches some times and seems to as you say skip from 1st to third gear.
 

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I've only owned the car for 5 days now (175 miles on the odometer), and this wonky transmission (cvt) lugging/surging bothers the **** out of me... I explained it as falling flat on its face or turbo lag when you're trying to apply steady gas/throttle from a dead stop. Some time it accelerates smooth, picks up speed like how you would expect it to, other times it feels like how GHP1 explained it "skips from 1st to third gear".

Going to put atleast a 1000 miles on the car first and have the ECM try to learn from the driving habits. If this "issue" persists, then I'll request an ECM update.

Glad I stumbled on this thread
 
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I've only owned the car for 5 days now (175 miles on the odometer), and this wonky transmission (cvt) lugging/surging bothers the **** out of me... I explained it as falling flat on its face or turbo lag when you're trying to apply steady gas/throttle from a dead stop. Some time it accelerates smooth, picks up speed like how you would expect it to, other times it feels like how GHP1 explained it "skips from 1st to third gear".

Going to put atleast a 1000 miles on the car first and have the ECM try to learn from the driving habits. If this "issue" persists, then I'll request an ECM update.

Glad I stumbled on this thread
I would wait until the break in is complete but mine has not changed and I'm at 2,800 miles
 

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Learning?

Back in December when we had our first oil change completed, I voiced a concern about a hesitation (like it missed 2nd gear and went directly to 3rd). Dealer reset the ECM and then told me that it "learns" your driving habits for best operation. If you have two drivers (wife and I), then it's learning both driving habits and trying to find a compromise that works best for both.
Not sure if that's true, but if it is, then these "computers on wheels" need to be smarter and determine which driver's key fob is in the driver's seat and act appropriately with that driver, not trying to figure out some compromise. Just my .02 cents. :dunno:
 
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