general problems of the 2020 Toyota Corolla - part 1

On the morning of January 7, 2026, while I was on my way to work, I experienced a dangerous incident involving my vehicle. As I arrived at the first stop on the street, I suddenly heard a loud explosion. Immediately afterward, pieces of glass began falling onto my windshield. I pulled over and exited the vehicle to assess the situation. Upon inspection, I discovered that the sunroof of my car had completely shattered. Glass was scattered across the roof, windshield, and interior of the vehicle. Prior to the explosion, there were no visible signs of damage to the sunroof. The incident occurred without warning and posed a serious safety risk. I am submitting this complaint to formally document what happened and to request that the matter be investigated and addressed appropriately.

I was driving normally to work and the vehicle stalled without warning and became difficult to steer. The dashboard displayed “engine stopped, steering power low”. The vehicle was stalled in the middle of the roadway and could not be restarted for 10 minutes. This was a very dangerous way to stop and then not be able to restart. People had to get out of their vehicles and help me push it out of the roadway. After 10 minutes the vehicle started and drove normally without any issues. The battery and alternator tested good. The mechanic can not find anything wrong. I am scared to drive the vehicle now and have an accident due to this incident.

I’m getting engine maintenance required visit your dealer, and it has to do with the a/c it only comes on when I turn on the a/c which has to work the “coolant bypass valve” I’ve looked online and many others have had issues it’s the 2020 and onward year Toyota, I’m not the only one many have mentioned they reach out the dealer & state this is not a recall and need to pay out of pocket to fix, but with some many people having same issue, doesn’t seem right that it wouldn’t be a recall with its multiples of people having this same issue.

Engine maintenace required light came on. I was told that my coolant bypass valve needed to be replaced. This is happening on all Toyota vehicles from 2018-2024 common issue but the repair to fix something that should be covered under warranty.

When I use blinker windshield wipers turn on and sometimes when I call or somebody calls my cell phone I can hear them, but they cannot hear me. Does not happen all the time, but I was concerned since there was a recall on certain Toyota Corolla that says a short circuit may develop in the OCS sensor, preventing front passenger air bag from deploying and my son who is a mechanic said both of these could be a problem with the wiring in the column and I thought it may be connected to the same recall as the air bags? the wipers coming on is happening more often these days and that is why I mentioned it to my son who is a mechanic. He will not touch it since it is still under my extended protection but he is concerned about it getting worse since the blinker is attached to the column. As far as using not being heard by callers or when I call I am concerned if I need to call in an emergency the ones I call cannot hear me. As far as when this started I do not remember but I know it's been at least 6 months if not longer, it just seems to be doing it more often lately.

While driving with the windshield wipers on during a rain storm , the wipers would stop working suddenly. The car was taken to dealer and windshield motor was replaced. Without working wipers, it was dangerous to drive.

An engine maintenance required warning popped up. The pop up wasn't going away. My engine sounds louder than usual when turning my a/c on.

Engine coolant bypass valve.

Once I parked my car and turned on the a/c a couple mins later I received a warning message on my car screen saying “ engine maintenance required visit your dealer”. After having my car for 4 years I’ve never received this message till now (04/22/25). I thought it was because I needed an oil change but I was wrong because my oil is good. I checked my car and saw that the issue is the “coolant bypass valve”. I don’t even use my car that much for this to happen. I saw this is a common issue with a Toyota Corolla 2020 but the dealership does not want to fix this issue for free.

Coolant bypass valve. Code is p2681, part will fail and vehicle will consistently display a engine maintenance required visit your dealer on the mid. Dealerships will try and charge 500+ to repair it when the part is under 100+. Problem started to appear since end of March. It's may 15th as of this report. Upon using an obd tool this is the following message: "status confirmed / pending - engine coolant bypass valuve 'a' control circuit/open : circuit short to battery or open". Part has not been inspected by Toyota, nearby service centers are scumbags and will charge a fortunate to fix it.

Front is very low. Right side is tilted without anyone inside. Very unusual tire wear on inside edges of both front tires. Immediately after starting the engine the front ricked side took side and made loud noises.

Coolant bypass valve needs to be replaced.

Engine maintenance required notification came on. Car is only 3 years old. Dealership stated that the coolant bypass valve needs to be replaced and it could potentially cause a fire. Service professional at the dealership stated that this is a common issue and most of the time Toyota warranty doesn’t want to repair it, also said that it should be recalled. I have also seen hundreds of people complain about this on rav4 forums.

I have a 2020 Toyota Corolla. "engine maintenance required; visit your dealer" came on the display after I brought my car to the dealership. I returned to the dealership and was told it was $250 to diagnose the problem. I waited a month later and brought my car back for an 80,000 inspection at the longo Toyota in prosper texas. They diagnosed the problem this time and said they would have to replace the coolant bypass valve and hose for ~$800 plus labor costs. The risk of not repairing these parts is possible engine failure or fire. I've seen many other discussion forums where people are experiencing the same problem with rav4, Corolla, and camry models 2020-2023. These parts are not covered under warranty and would have to pay out of pocket for the repairs. Toyota should issue a recall since many people are reporting these same issues, creating out-of-pocket costs for the repairs for >$800.

Toyota Corolla 2020 engine coolant flow control valve.

The check engine light came so I took it to Toyota dealership. I paid 300$ to get a diagnostic and they said it was my coolant bypass valve and it was 900$ to fix. Warranty doesn’t cover this even tho my car qualifies for the coverages. It’s super frustrating since I bought this car brand new and im having multiple expensive problems. I need to replace the transmission, brake actuator, oil replacement pan and I had to replace a brand new battery because it exploded after only using for less than a year.

Coolant bypass valve. Becoming persistent in several models of Toyota 2019-2021. Dealerships claim it’s not covered under powertrain warranty because it’s part of the coolant system. Should be covered and customer should be compensated or reimbursed.

Got an engine maintenance required light show up, took my car to the dealer to diagnose, they stated that I need to replace my coolant bypass valve.

Engine coolant bypass valve has gone bad and presents a 'engine maintenance required, see dealer' error message.

Engine maintenance required see dealership message on dash. Coolant valve needs to be replaced. Class action lawsuit pending.

The car will need a new coolant by-pass valve ($663 installed). This is a problem that seems to be affecting more cars than usual as it is in many websites and social media portals, but it's not recognized to be recalled!! a $70. 00usd part for $663. 00 installed??.

The coolant valve in the engine began malfunctioning and leaking next the the battery. I took it to the dealership and they said that this was a common maintenance issue, but it is do to the part being faulty overall. This is a widespread issue with this make and model of the vehicle and the part has not been recalled. Leakage could possibly cause the engine to overheat and the result could be catastrophic.

My 2020 Corolla xse has been displaying an "emergency maintenance alert" for over a month covering the middle portion of my dash. When running the code it indicates "coolant valve" defect. Upon further research while trying to obtain a replacement part it looks as though multiple people are having an issue with the same part.

Coolant bypass valve issue.

My family has several Toyota vehicles but for some reason my 2020 Toyota Corolla is the only one that comes up with problems. My engine maintenance required notification came on for my 5 year old vehicle. The dealership stated that the coolant bypass valve needs to be replaced and that it was a common issue. They are saying it cost almost $1000 just to fix an issue created by them on a new car with 55,000 miles.

My car had 55,930 miles on it. That day I was at home bout to go out & my car wouldn’t start. The dashboard display said “ignition on” but the engine wouldn’t start. • the dashboard display also said other things like— check engine, or drive start control malfunction/ brake override malfunction/ braking power low/ engine maintenance required. • the dashboard display persisted. • my car has been at a local repair shop since 8-6-24 & is still there. • my complaint is re the 2020 Toyota Corolla water valve coolant bypass valve. • the repair shop told me my car had a cracked water valve. I was also told that a harness connector in my car is burnt or singed & my transmission isnt working. • I asked the repair shop if the cracked leaking water valve in my car could have caused my car problems & I was told, no it could not have caused the car problems. • however contrary to that & per news I read— it was found that Toyota’s coolant bypass valve water valve, in 2020 Corollas, is defective, & that it can crack & leak & cause operational car malfunctions & damage to the car or to its coolant system or to other components including to electrical system or to water valve sensor or ecm or cause car failure or engine damage as well. • I am just a layperson but at times my car hood would feel hot, & smelled “hot”, but I thought it was just because I had been out driving around & everyday its usually always sunny & hot in my city. • I was also told by the repair shop that a technician has been running test after test on my car to find the problem & its been very difficult & that there’s been around 20 different diagnostic trouble codes that have accumulated over the course of testings on my car. But they don’t know what is wrong yet. A different mechanic said my car had electrical system related communication issues. I believe the defective Toyota water valve caused my car’s problems also rendering my car unsafe & inoperable. I don’t have room to write everything here.

Engine maintenance required, see the dealer msg started popping up. Went to the dealer and after diagnostic check, the dealer said the bypass valve need to be replaced and wont be covered under powertrain warranty.

The coolant bypass valve is failing. Engine maintenance required message popped on car display. Toyota is trying to charge over $600 to fix it. Many have reported same issue.

Coolent valve.

I have a message that says engine maintenance required. I ran a diagnostic and it is for the engine coolant bypass valve.

At 55k miles for my 2020 Toyota Corolla, the engine maintenance required notification popped up on my screen and is not removable. Upon further verification numerous 2020-2021 Corollas have been having this issue at similar amounts of mileage. It is a faulty engine coolant bypass valve that needs to be replaced. If I were to take it in to a dealership, they would charge $500+ just as they have for many others when it should really be a recall. As of now I have not taken it to be inspected due to fear of steep labor costs. My safety is at risk because if this does not get replaced my engine will overheat causing total failure of the car, and as a 2020 model with such low mileage, this is ridiculous.

Check engine light is giving a false positive. There is something wrong with the coolant bypass valve. I checked online and this is not an isolated event.

Coolant bypass valve failed at 52k miles.

Maintenance required please see dealer message pops up and cannot be dismissed. Coolant sensor bypass valve is damaged.

My son and daughter in law moved from California to georgia due to military duties in hinesville georgia. They drove their 2020 Toyota Corolla from California to georgia. They paid the fee to obtain their 2024 registration sticker but got denied by the dmv in California due to a recall on this vehicle. My son took the vehicle to chatham parkway Toyota in savannah georgia to fix the recall. He received documentation that the recall has been fixed. My daughter in law took this documentation to the dmv and they said it was not sufficient, we needed to provide the original pink copy of the recall. Chatman parkway Toyota never gave my son the original copy. Where can we obtain this so we can receive our registration sticker? can you please help us out and contact chatham parkway Toyota to see if they even fixed the recall problem or not and why they did not give my son an original copy of the fixed recall situation. It has been a struggle to obtain the registration sticker when the recall was a problem. This situation has been very stressful due to an expired registration and not being able to drive u til we receive the correct sticker. Please help if you can. Thank you, gloria mcgarvey. 415-420-4774.