79 of the 395 complaints about the 2020 Toyota Corolla are about the other systems — 20% of everything reported for this model year. Half of the failures with a mileage on record happened before 1,200 miles.
79
Complaints
4
Crashes
0
Fires
2
Injuries
Filed with NHTSA, in their own words.
UNKNOWN OR OTHER
Replace Heater Control Valve - Diagnostic code P2681 indicates an internal electrical failure within the heater control valve assembly, a condition commonly seen on Toyota vehicles. Testing showed the electrical portion of the valve is open and no longer maintaining proper circuit continuity, requiring replacement of the heater control valve assembly.
NHTSA complaint #11739095 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
Coolant water control valve short circuit. Causes dealer message that won't clear and dealer wants $600 to replace a $30 part. Part is extremely difficult to get to and should not be a wear item.
NHTSA complaint #11730593 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
Car shows the below message when A/C is turned on: Engine Maintenance Required Visit Your Dealer
NHTSA complaint #11729914 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
Message on dashboard that says, "Engine Maintenance Required. Visit Dealer." This message came on at around 31,000 miles and I was told it was three different things all different prices at my dealer. So, I looked into it and found out it was the Coolant Bypass Valve, and asked the dealership about it and they said 700 dollars to replace. I did not want to pay that much especially since I saw online others were having the same problem. Message still pops up to this day when I turn on my A/C. Car now has around 205,000 miles on it and is six years old.
NHTSA complaint #11724474 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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
NHTSA complaint #11714511 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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.
NHTSA complaint #11711360 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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.
NHTSA complaint #11695131 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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
NHTSA complaint #11688004 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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.
NHTSA complaint #11679742 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
Front windshield has bubbles on all the edges and they are getting bigger i took it to the warranty ofrece and they say it not a defect, but i hace sean more tan 100 cars With the same problem ,and i don't fiel sale wathching then grow or break. I hope You can verify , just look at any corolla and You Will see what i say on the edges of the windshield, thank
NHTSA complaint #11667575 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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.
NHTSA complaint #11661513 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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.
NHTSA complaint #11661352 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
Engine Coolant Bypass Valve
NHTSA complaint #11660308 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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.
NHTSA complaint #11656209 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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.
NHTSA complaint #11643500 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
Coolant bypass valve needs to be replaced
NHTSA complaint #11643216 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
"Engine maintenance required" - Coolant bypass valve is the cause
NHTSA complaint #11626369 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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.
NHTSA complaint #11626281 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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 >$800.
NHTSA complaint #11622233 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
Toyota Corolla 2020 Engine Coolant Flow Control Valve
NHTSA complaint #11621151 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
the check engine light came so i took it to toyota dealership. i paid 300$ 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.
NHTSA complaint #11617518 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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
NHTSA complaint #11613566 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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.
NHTSA complaint #11613184 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
Engine Coolant Bypass Valve has gone bad and presents a 'Engine Maintenance Required, see Dealer' error message.
NHTSA complaint #11613232 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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.
NHTSA complaint #11611946 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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.
NHTSA complaint #11609721 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
Engine maintenance required see dealership message on dash. Coolant valve needs to be replaced. Class action lawsuit pending.
NHTSA complaint #11609088 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
Engine Coolant Bypass Valve
NHTSA complaint #11608772 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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??
NHTSA complaint #11606462 — an unverified report by a vehicle owner.
UNKNOWN OR OTHER
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.
NHTSA complaint #11603754 — an unverified report by a vehicle owner.