# Holding 5th gear on highway?



## CruzeRSTN (Jan 4, 2018)

Hey, I have a 2018 Premier RS and noticed lately while doing 120km/h it’s sitting at about 3200RPM and won’t upshift to 6th. If I accelerate to 130km/h it will shift up to 6th but it’s a rough shift and setting cruise at 130km/h it doesn’t know what to do and constantly shifts up/down/up/down. Above 130km/h it will stay in 6th. Currently has 43,500km never had a problem with the car so far, any ideas?


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## jblackburn (Apr 14, 2012)

That is super weird. Mine goes into 6th around 42-45 most of the time unless you're on it to merge. I have never seen it hunt gears on the highway. 

Is it down on power? Maybe leaking boost? 

In any case I'd take it into a dealer and have them look at it. 

Sent from my SM-G950U using Tapatalk


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## CruzeRSTN (Jan 4, 2018)

It’s my commuter car so I don’t reall step on it much, set cruise and go. Last night on the way home it went into 6th gear for about 80% of of the drive and then near home randomly downshifted again. It’s going in today and I’ll post an update incase anyone else runs into the problem later


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## thecat77 (Aug 8, 2019)

I also have a 2018 Cruze LT turbo rs. My car also won't go into 6th gear. Just started today. I know this is old but did you ever find out the problem?



CruzeRSTN said:


> It’s my commuter car so I don’t reall step on it much, set cruise and go. Last night on the way home it went into 6th gear for about 80% of of the drive and then near home randomly downshifted again. It’s going in today and I’ll post an update incase anyone else runs into the problem later


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## nathanroe72 (Nov 25, 2016)

thecat77 said:


> I also have a 2018 Cruze LT turbo rs. My car also won't go into 6th gear. Just started today. I know this is old but did you ever find out the problem?


Is your engine coolant temp within check? If the ECT is reading low, it won't upshift/lock the TC. I would recommend scanning for codes and report back.


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## Rshatchredline (Feb 10, 2019)

I just had this happen to me as well was fine this morning when I came home from work made a 45 min drive back to the city and remained at 3500 rpm on the highway. No engine light, coolant temp at half as it should be. Tryed to switch to manual and placed in 6th with no change. Called dealer it’s going in for that and a loose antenna on the roof


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## Slaw0042 (Dec 27, 2019)

Anyone ever get any answers? Mine is doing the same thing. 60k miles.


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## Rshatchredline (Feb 10, 2019)

According to the head tech at my Gm dealer the 1.4l will hold 5th to prevent inter cooler from freezing up during cold high humidity conditions. My car has returned to shifting to 6 only held 5th for a few days.


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## Slaw0042 (Dec 27, 2019)

Wow, that's really odd. But thanks for the reply. Now I know.


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## Rshatchredline (Feb 10, 2019)

Yea I found it odd as well lol


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## Slaw0042 (Dec 27, 2019)

Mine has been doing it a lot more here lately, today I never even got into 6th gear. It was in the teens outside today but it's getting more concerning. My fuel consumption is massive now. I drive 110 miles a day so it's just been drinking gas.


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## bvice (Jan 21, 2020)

CruzeRSTN said:


> Hey, I have a 2018 Premier RS and noticed lately while doing 120km/h it’s sitting at about 3200RPM and won’t upshift to 6th. If I accelerate to 130km/h it will shift up to 6th but it’s a rough shift and setting cruise at 130km/h it doesn’t know what to do and constantly shifts up/down/up/down. Above 130km/h it will stay in 6th. Currently has 43,500km never had a problem with the car so far, any ideas?


Same for me did you ever find out why?


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## bvice (Jan 21, 2020)

Slaw0042 said:


> Mine has been doing it a lot more here lately, today I never even got into 6th gear. It was in the teens outside today but it's getting more concerning. My fuel consumption is massive now. I drive 110 miles a day so it's just been drinking gas.


Did you ever find out why


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## Slaw0042 (Dec 27, 2019)

Rshatchredline said his tech said it was designed to do so. I still don't see the reasoning behind it. Not like the intercooler is full of water or anything. I've owned a lot of turbo cars and this is the first one to do this.


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## bvice (Jan 21, 2020)

Yeah I know , this is the first yr doing it , 2018 102000 miles i wonder if the fluid would have anything to do with it , i didnt know about changing it that often but it's never been changed , no check engine light or anything


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## bvice (Jan 21, 2020)

CruzeRSTN said:


> Hey, I have a 2018 Premier RS and noticed lately while doing 120km/h it’s sitting at about 3200RPM and won’t upshift to 6th. If I accelerate to 130km/h it will shift up to 6th but it’s a rough shift and setting cruise at 130km/h it doesn’t know what to do and constantly shifts up/down/up/down. Above 130km/h it will stay in 6th. Currently has 43,500km never had a problem with the car so far, any ideas?


Yeah I know , this is the first yr doing it , 2018 102000 miles i wonder if the fluid would have anything to do with it , i didnt know about changing it that often but it's never been changed , no check engine light or anything


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## -loki- (Dec 13, 2019)

High humidity content on in coming air could condense inside the intercooler after being heated by the turbo then cooling down causing water vapor to form in the inlet tract. Ever taken a tupper ware out of the fridge and have water on the inside of the lid. Same thing basically.


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## Slaw0042 (Dec 27, 2019)

I can kinda see where you're coming from with that. It's just the first car I've ever had that would do that.


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## bvice (Jan 21, 2020)

Slaw0042 said:


> I can kinda see where you're coming from with that. It's just the first car I've ever had that would do that.


Did you try that with yours


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## Slaw0042 (Dec 27, 2019)

I was replying to Loki. But no. I have not changed the trans fluid at all. From what I can gather it is in the software tune, so I imagine changing the fluid wouldn't really help. 

I would however like to know the parameters in which it happens. My auto start stop doesn't work either (no complaints there) but it didn't do any of these things last winter. It only started this winter so I would like to know how the ECU/PCM knows when to hold 5th gear.


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## -loki- (Dec 13, 2019)

I'm sure there's all sorts of ideal gas laws and chemistry/physics equations that some engineer thought.hey we should make the car do this to prevent a condensation condition that could damage the engine...


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## bvice (Jan 21, 2020)

Cruising down the road it stays in 5th , punch it get it up like 80 it goes into 6th speed drops to like 60 it goes back to 5th it use to not do that


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## Slaw0042 (Dec 27, 2019)

Mine won't go into 6th at all. No matter what.


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## bvice (Jan 21, 2020)

Even when weather is warm?


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## Slaw0042 (Dec 27, 2019)

Only when it's cold.


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## PolarisX (Dec 17, 2017)

Hey dumb question. Is your outside temp sensor accurate? It's possible your car thinks it way colder out than it might actually be?


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## Slaw0042 (Dec 27, 2019)

Good idea, but yes it is reading correctly.


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## Slaw0042 (Dec 27, 2019)

I wonder what the manual transmissions do to compensate for this moisture.


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## bvice (Jan 21, 2020)




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## bvice (Jan 21, 2020)

Happy Reading


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## Slaw0042 (Dec 27, 2019)

Well. That settles that. Thanks for the info.


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## 2019Cruze3078 (Jan 22, 2020)

-loki- said:


> High humidity content on in coming air could condense inside the intercooler after being heated by the turbo then cooling down causing water vapor to form in the inlet tract. Ever taken a tupper ware out of the fridge and have water on the inside of the lid. Same thing basically.


If that is the case I can understand until the engine and vehicle is warmed up. Cruising on the highway at highway speeds will out the transmission in 6th gear and about 2300-2500rpm. With that being the case would driving in town not possibly cause the same thing with the moisture as the car isn’t reaching high revs but is stopping sand starting so the temp would go up and down.


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## 2019Cruze3078 (Jan 22, 2020)

We picked up our dealer 2019 demo Cruze last week and noticed it on the way home revving high and not going into 6th gear. Everything I have read is that normal transmissions in cold weather may shift at higher revs and may not shift into overdrive but everyone says that once the car warms up the transmission shift fine including into overdrive. I have spoken to multiple mechanics including a transmission specialist that this is not normal and the computer system thinks the vehicle isn’t warm enough and isn’t locking into gear. They all said it makes no sense. I have attached a copy of what GM gave me the other day. It states that SOME, not most or all, but some customer have said that in cold temperatures with high humidity that the car doesn’t shift into overdrive. There answer is that it senses moisture and it prevents freezing in the charge container (I think that’s what it’s called). They said it is programmed like that. I call BULLSHIT...if it was programmed to do that then why did my dealership have no idea about this problem after selling and working on hundreds of vehicles and it and why only some not all. To me this just seems like a cover up for something defective that will cost them money to fix. I don’t think it’s the transmission but a programming issue. It is not normal for a vehicle that has driven 2 hours on the highway to be revving at 3200-3300rpm. That why they are equipped with overdrive. Let alone that the mpg are incorrect for these vehicles and is misleading. My guess is that this happens in probably less then 5% of the 2018-2019 models maybe even as low as 1-2%. That tells me it isn’t normal and there is a problem. COVER UP on a vehicle that they discounted. I am not done with this on my end. I am taking this to the papers, tv stations and anyone that will listen. Myself and my family worked at the Oshawa Canada plant that just closed and we’re all let go. I’m not getting ****** twice by this company.


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## jblackburn (Apr 14, 2012)

I have definitely had moisture get stuck in my IC during cool, rainy weather (low 30's).

Cruising along in 6th at 2000 RPM for hours and if you suddenly step on it to pass or something, I've had my car kick down a few gears, and then fall flat on its face and pull power severely as that moisture buildup in the IC gets shoved into the engine.

It will eventually respond normally again, but it's definitely disconcerting.

This appears to be GM's answer to that; I personally believe a weep hole in the intercooler would do the trick just fine.


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## PolarisX (Dec 17, 2017)

We have a 2016 and 2017 2nd gen. I've never seen the 5th gear or icing IC issue. It might just be where we live though?


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## jblackburn (Apr 14, 2012)

PolarisX said:


> We have a 2016 and 2017 2nd gen. I've never seen the 5th gear or icing IC issue. It might just be where we live though?


The 6th gear lockout programming seems to only apply to 2018-2019 MY according to that documentation above


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## 2019Cruze3078 (Jan 22, 2020)

It a


PolarisX said:


> We have a 2016 and 2017 2nd gen. I've never seen the 5th gear or icing IC issue. It might just be where we live though?
> 
> they say it is only with the 2018 and 2019 cruzes and only some of them, not all.


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## 2019Cruze3078 (Jan 22, 2020)

jblackburn said:


> I have definitely had moisture get stuck in my IC during cool, rainy weather (low 30's).
> 
> Cruising along in 6th at 2000 RPM for hours and if you suddenly step on it to pass or something, I've had my car kick down a few gears, and then fall flat on its face and pull power severely as that moisture buildup in the IC gets shoved into the engine.
> 
> ...


I could accept that being GM’s answer if this was the case in most to all of the 2018-2019 Cruze’s but this only happens to a very small percentage of them. The dealership I took it to didn’t even know about this issue. If that is the way it was programmed then it wasn’t programmed that way in most of them. I believe this is a programming issue then and will eventually case engine problems.


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## jblackburn (Apr 14, 2012)

2019Cruze3078 said:


> I could accept that being GM’s answer if this was the case in most to all of the 2018-2019 Cruze’s but this only happens to a very small percentage of them. The dealership I took it to didn’t even know about this issue. If that is the way it was programmed then it wasn’t programmed that way in most of them. I believe this is a programming issue then and will eventually case engine problems.


Can't see it causing engine issues, just wasting gas.

They run engines wide open at redline for days during testing.


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## 2019Cruze3078 (Jan 22, 2020)

jblackburn said:


> Can't see it causing engine issues, just wasting gas.
> 
> They run engines wide open at redline for days during testing.


when your commuting on the hwy everyday revving at 3200-3300rpm put adds wear and tear on the engine. That’s why they have overdrive.


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## jblackburn (Apr 14, 2012)

2019Cruze3078 said:


> when your commuting on the hwy everyday revving at 3200-3300rpm put adds wear and tear on the engine. That’s why they have overdrive.


Never harmed a single Honda on the road running 3500+ RPM down the highway.

There's no case for added wear and tear, but you can make one for fuel consumption. That's about it.


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## gacl (Jan 22, 2019)

Off topic, but has ur 2018 had any issues up to 102,000 miles other than the one stated above?


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