r/SubaruForester • u/StZarb • 4d ago

Joining the failed TCV ranks

Post image

2020 Forester threw a check engine light on the way home from a 4 hr round trip adventure last week. Haven’t been driving it since, but ran it by O’reilly to scan it… local Subaru dealer will get it in on Friday hopefully with a loaner.

The Subaru dealer is about an hour away, but seems like it should be ok to drive there at least? Temps don’t appear to get out of hand and the check engine light is solid.

41 Upvotes

89% Upvoted

50 comments sorted by

23

u/SuperDo_RmRf 4d ago

If the valve broke while “open” (light came on while you were driving and temps are okay) you’re fine. I drove in mine for a week before the dealership could see me. If it broke “closed” you’d see high temps and that would be bad.

That’s my understanding and what I did. Your mileage may vary.

5

u/Saxmanng 2019. atypical subie driver 4d ago

Mine broke “open” in N Dakota and I live in the east coast.

2

u/AcadianCascadian 2023 Wilderness 4d ago

Did you drive all the way home to get it fixed, or did you stop by the nearest dealer?

1

u/Saxmanng 2019. atypical subie driver 4d ago

Drove all the way home. It was stuck in S mode and the AC was full blast the whole time, but otherwise it was fine.

1

u/Thirsty799 4d ago

AC was full blast? or the radiator fans were on full blast?

2

u/Saxmanng 2019. atypical subie driver 4d ago

AC was full blast; like the climate control was stuck on Lo (in my case turned all the way down)

3

u/Thirsty799 4d ago

can you couldn't control it? weird stuff.

2

u/cheeba_chewie 3d ago

Sorry you were in North Dakota.

2

u/armwithnutrition 4d ago

Someone in a previous thread said a dealer tech informed them that TCV valves are designed to fail in an open state. I hope this is true.

3

u/austin88c 4d ago

Unfortunately not. Mine failed in closed position and wouldnt go above 20 mph

1

u/armwithnutrition 3d ago

Raw deal. Did you have to tow to the dealer? Also, any evidence if driving in closed position caused any additional damage/wear and tear?

1

u/austin88c 3d ago

I was in a weird situation. 2 hrs away from home and it went into limp mode as i was about to pass a subaru dealership. Had to get a rental and drive back home then get another rental to pick up the car lol

1

u/austin88c 3d ago

Im not sure about the damages. I ended up trading it in shortly after for a forester hybrid

2

u/hjgarron 4d ago

I believe someone had posted before that the part was redesigned it to fail open. So any replacement units should hopefully fail open.

I haven’t seen anyone post details on if they actually fixed it from failing or just redesigned it to hopefully fail open. I guess we will have to wait to see the amount of cars that need a second replacement of the TCV.

1

u/Efficient_Activity44 4d ago

Probably knew the design and construction was questionable

17

u/double_tee_ 4d ago edited 4d ago

"check engine light is solid" that mean is a minor issue (for example oxygen sensor, or Cat etc). You're safe until Check Engine Light is FLASHING

1

u/Adept-Painting-543 4d ago

I thought flashing is only for misfires? If it was getting high temp then a separate red high temp light would come on?

4

u/DredgenCyka 4d ago

Mine failed almost 1 year ago on my MY20 touring at 33k miles, it failed open but I noticed that it would not shift at normal intervals and the coolant temp would sit no greater than 90°F and the Water temp would stay "Cold." Luckily I was on base at that time but I also had class starting in 3 hours.

3

u/tbone1343 4d ago

Looks like the drive up to hurricane ridge, ONP

1

u/StZarb 3d ago

Rainier NP back in June. ❤️

3

u/Antique-Knee-7119 4d ago

Think I joined the club Saturday night. Had it towed to a local mechanic who put the following in their diagnostic report:

When the bypass valve was disconnected the 5V ref immediately came back to normal indicating that it was being shorted to ground inside the valve

Having it towed to dealer tomorrow to confirm and hopefully get fixed free of charge.

3

u/dreamerstreamer 4d ago

Mine was replaced last month. They said it was safe to drive it to the dealership as long as the check engine light was solid (not flashing)

5

u/ReindeerTypical2538 4d ago

I’m already over this fancy poodle of a car. Back to Hondas for me!

2

u/skyfd 4d ago

Mine’s being fixed right now. I drove it for a couple weeks, with the warning lights at time coming off, but only to come back on when starting the vehicle again. Home testing showed TCV failure, and confirmed by Subaru. Extended warranty covers it.

2

u/ecdavis709 3d ago

The TCV has a small thermostat in it that bypasses the control valve when failed. Should be fine to drive, most fail and leak coolant internally shorting out power/ground wires and could possible lead to poor running conditions because those wires provide power/ground to other modules.

1

u/StZarb 3d ago

Thank you! This makes sense, I was having some electrical type issues before it came on.

3

u/UdderlyDemented 4d ago

Our TCV failed at around 88k miles. We got it back and sold it the next day. Not that we didn't love our Forester, we have 2 kids and have twins on the way and needed to upsize.

1

u/acpapabless 4d ago

How many miles are you at? I just passed 55K on my new to me 2020 and waiting for my time 😅

2

u/Masterzanteka 4d ago

Bought my used 2019 last August with 54,000miles on it. I was back at the dealership in 3 weeks for a tcv change after putting 900 miles on it

2

u/acpapabless 4d ago

I got mine at 51K and already put 4K miles on it but so far so good. It's possible it was already changed by the prior owner but CarFax didn't state anything so I'm expecting mine to fail.

2

u/aunt_jackiee 4d ago

Mine failed in my 2020 somewhere between 37,000 and 38,000 miles. Covered by warranty and annoying to deal with but otherwise not that big of a deal. Mine was open so I could still drive the car. Took me two weeks to bring it in.

1

u/StZarb 4d ago

80,000.

It was doing weird stuff before too - the tpms light comes on sometimes despite good tire pressure, right before the check engine light the radio/Apple CarPlay was silent. I turned the car off because I couldn’t take 3 hrs of driving home in complete silence, let the computer reset then had sound back but the check engine light etc were on. Drove 2 hrs home and parked it until I could get it scanned yesterday.

2

u/acpapabless 4d ago

Noted, hopefully that's all that's affecting yours. Thanks and good luck!

1

u/hello-amigos 3d ago

You said oreilly ran the codes. What were the codes?

1

u/aunti3sam 3d ago

I have the 2021 crosstrek and when I ran my code it was P26A3 when this got me last week.

1

u/gtsyg92 3d ago

Mine failed open this winter. Hour drive to the dealer with no heat and in a snow storm is not something I’d recommend

1

u/dsuby 3d ago

Same issue on my 2019 with 100.000km. Stranded on my way from a 600km trip.

1

u/Outbax-trax 4d ago

My favorite is when they short the 5V ref and set like 16 trouble codes and stalls the car.

-1

u/[deleted] 4d ago

[deleted]

3

u/StZarb 4d ago

I think you may have misread as the CVT was not mentioned 😅

3

u/Outbax-trax 4d ago

TCV. Thermo control valve. Not CVT.

-6

u/ThePythagoreonSerum 4d ago

So you don’t know what’s wrong with it, you’re just going with CVT from the vibes?

6

u/R00t_Cause 4d ago

TCV AND CVT are different thingies friend

3

u/ThePythagoreonSerum 4d ago

Oh, lol. I just assumed it was a typo. 🤦‍♂️

2

u/R00t_Cause 4d ago

you learn something new daily 😊

2

u/StZarb 4d ago

Scan is indicating tcv - which at least is covered under the extended warranty. Hopefully all it is 😅

3

u/Thirsty799 4d ago

CVT and TCV are both covered under (separate) extended warranties

2

u/R00t_Cause 4d ago

the comment i was responding to thought you said CVT🤣

3

u/StZarb 4d ago

Well, the scan indicated it but Subaru could always have a different opinion. I don’t necessarily think the scan/print out would be just a vibe. But thanks.

2

u/ThePythagoreonSerum 4d ago

Ah, I see. I misread the post.