1,351 of the
14,546 complaints filed about the Toyota Corolla
are about the engine —
9% of everything owners reported.
The worst model year for it is 2009.
Part is the coolant bypass valve. Toyota has been taken to court but dealership claims now that I’m over 100k miles I can’t do it. There was also a second part about 10 years but I wasn’t clear on the details of the outcome. Toyota has acknowledged this issue in court but failed to do so at the customer level in my case. engine light came on at 97k and now I’m at 104k which is over that 100k mark. Issue is I’ve only take my car to Toyota for repairs. They have known about this but failed to repair or notify me of it. I would have immediately brought my car in at 97k if. I had known. This puts not only me but my 3 kids and entire family at risk every time i drive. This is known to the dealership and they been taken to court for failures to notify customers of this known defect. It’s been inspected by Toyota the last time I took it in about a week ago at 104k miles.
NHTSA complaint #11755244 — an unverified report by a vehicle owner.
While driving in the middle of active traffic, the vehicle experienced a sudden and dangerous loss of motive power. The first indication of a problem was the A/C abruptly blowing hot air. Immediately following this, the vehicle began violently shaking before the engine stalled completely. The low oil pressure warning light was triggered on the dashboard. Losing all acceleration in the middle of active traffic created an immediate, severe crash hazard. The engine failure occurred after a franchised dealer service department failed. They had said at the dealership that my oil was fine. They didn’t even check it.
NHTSA complaint #11752412 — an unverified report by a vehicle owner.
This Toyota Corolla hatchback is experiencing an issue where it is constantly giving an “ENGINE MAINTENANCE REQUIRED” light and when scanned, it says “coolant bypass valve malfunction”. There is already a recall for many Toyota Corolla Sedans experiencing this issue of this bypass valve being defective, but because this is a hatchback, it is not part of the recall when it should be. There is already a recall for vehicles affected with this issue: T-SB-0112-24
NHTSA complaint #11751893 — an unverified report by a vehicle owner.
Notification spontaneously received as Engine Maintenance Required; Visit Your Dealer. Service appointment immediately scheduled for Toyota of Plano for the following day. My service advisor recommended replacing the coolant bypass valve, which amounted to a total bill of $745. My agent informed me of CSP 24TE04, however my service advisor didn’t acknowledge any eligibility of VIN pertaining to it. Toyota Brand Engagement Center also did not report any eligibility of my VIN number for secondary coverage reimbursement despite it meeting the criteria exactly.
NHTSA complaint #11751945 — an unverified report by a vehicle owner.
I own a 2026 Toyota Corolla purchased in November 2025. The recurring problems began on December 8, 2025, when multiple warning lights appeared on the dashboard along with the message “System Malfunction – Visit Your Dealer.” The warning indicators involved several vehicle safety and driver-assistance systems. The vehicle was taken to an authorized Toyota dealership for inspection and repair. On June 16, 2026, the vehicle experienced another serious malfunction, including a “Transmission System Malfunction” warning. The electrical and operational problems continued despite dealership visits and repairs. The battery was also replaced, but this did not permanently resolve the recurring failures. During a later incident while the vehicle was being driven, multiple warning lights appeared and the vehicle lost power or shut off. There was no crash or injury, but the unexpected malfunction while driving created a serious risk to the driver, passengers, and other motorists. The dealership has also addressed an issue involving the shift lever position sensor and corrosion or water intrusion. I do not know the exact component responsible for all of these failures. However, the problems have occurred repeatedly since December 2025 despite multiple dealership visits. Toyota was notified and corporate Case No. 260630000224 was opened. I have not received a permanent explanation or resolution, and I am concerned that the vehicle could unexpectedly malfunction or shut off again while being driven.
NHTSA complaint #11751940 — an unverified report by a vehicle owner.
A message came on the screen saying “engine maintenance required” and it’s not going away. Upon doing a google search, there is a common failure in the cooling system for these cars reported by a lot of owners.
NHTSA complaint #11742614 — an unverified report by a vehicle owner.
The car that traps and holds moisture) in US vehicles are under recall. These "non-desiccated" inflators either have been or are required to be replace Ac don’t blow any cool air To be driving with a minor child it put he’s health in a bad risky situation
NHTSA complaint #11741585 — an unverified report by a vehicle owner.
The contact owns a 2022 Toyota Corolla. The contact stated that while driving at 50 MPH, the vehicle was hard to stop, and he lost control but was able to avoid a crash. The maintenance light was illuminated. Upon further research, the contact indicated the failure was related to TSB T-SB-0088-23. The vehicle was taken to the local dealer, where it was diagnosed and determined that the engine mount had cracked. The engine was hanging from the vehicle. The vehicle was not repaired. The vehicle was taken to an independent mechanic who had repaired the vehicle. The manufacturer was notified. The failure mileage was approximately 80,000.
NHTSA complaint #11740314 — an unverified report by a vehicle owner.
The vehicle displays an “Engine Maintenance Required” warning message shortly after the air conditioning is turned on. The warning does not usually appear immediately at startup but consistently appears when the A/C system is activated. The vehicle currently remains drivable, but the issue appears related to the engine cooling system and may involve the coolant bypass valve/flow control valve, which has been widely reported by other owners of similar model vehicles. The problem raises safety concerns because a cooling system malfunction could potentially lead to overheating while driving. The issue has been reproduced multiple times. A generic code scan at an auto parts store did not show stored engine codes. The vehicle was taken to a Toyota dealership and Toyota customer service was contacted regarding known coverage programs related to this issue, but the VIN was reportedly not included. Warning symptoms first appeared during normal driving and continue intermittently whenever the air conditioning system is used.
NHTSA complaint #11738354 — an unverified report by a vehicle owner.
Vehicle won't move. Emergency break malfunction notification came on. Unable to get to dealership without a tow. Diagnostic completed.. Quick service provided $701.66. Two A21 Cylinder Assy, RR DI @$402.90. Two A11 Actuator assy, parking @ $2168.34 also customer paid shop charge for repair order @ $99.00. Plus tax Total $3585.52 This car is a 2022 toyota corolla hybrid. Mileage at 78,000. This on flat ground in clients driveway, and the in emergency break was not used after turned off. Was inform is that the brakes looked in very good condition, so wonder why the emergency brake malfunction notification came on with Vehicle unable to move. Why was not explained.
NHTSA complaint #11737301 — an unverified report by a vehicle owner.
The contact owns a 2020 Toyota Corolla. The contact stated that while at a red light, the vehicle shut off with the check engine and several other unknown warning lights illuminated. The vehicle restarted after several attempts. The vehicle was taken to an independent mechanic and the failure was duplicated. The mechanic retrieved DTC: P1603; "Engine Stall History" (ECM recording an unexpected engine shutdown or a communication error with the Transmission Control Module (TCM). The mechanic associated the failure with NHTSA Campaign Number: 20V682000 (Fuel System, Gasoline) and referred the contact to the dealer for assistance. Several dealers were contacted, and the contact was informed that the VIN was not included in the recall. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 59,000.
NHTSA complaint #11733489 — an unverified report by a vehicle owner.
The component that failed is the coolant bypass valve, which is part of the engine cooling system. The vehicle is available for inspection upon request. The issue was first indicated by an "Engine Maintenance Required" warning message that appeared on the dashboard. No prior symptoms were noticeable before the warning appeared. The warning came on suddenly during normal driving conditions. This failure poses a potential safety risk because the coolant bypass valve regulates engine temperature. If it malfunctions, it may lead to improper engine cooling, overheating, reduced engine performance, or sudden breakdown while driving. This could increase the risk of being stranded in traffic or experiencing a hazardous situation on the road. The problem has been diagnosed and confirmed by an authorized Toyota dealership, which identified the coolant bypass valve as failed and in need of replacement. The dealership provided a repair estimate of $775 prior to taxes and fees. The manager shared that it would be around $890+ after it is all calculated. The vehicle has not been involved in any accident related to this issue, but the malfunction was verified through dealer inspection. No police or insurance reports were filed, as this was a mechanical failure. Based on personal research, this appears to be a widespread issue affecting similar Toyota vehicles, including other Corollas and RAV4 models, where the same component has failed under similar conditions. In some cases, repairs have been covered by the manufacturer, indicating awareness of the issue. There are many groups on Facebook and Reddit where customers with the same make and model 2022 Toyota Corolla SE have had the same issue after 3 years of having the vehicle. In summary, while driving under normal conditions, the warning message appeared without prior indication. The dealership later confirmed that the coolant bypass valve had failed and required replacement.
NHTSA complaint #11727887 — an unverified report by a vehicle owner.
Engine maintenance required, call dealer. The engine coolant bypass valve needs to be replaced. Known issue in Toyota corolla’s yet no recall to remedy the repair.
NHTSA complaint #11726859 — an unverified report by a vehicle owner.
Error message that said 'drive start control malfunction. Took 6 mos and numerous attempts to resolve. Replaced numerous parts including the fuel pump because the plastic it's made out of was just disintegrating and and cracking. This has cost thousands of dollars in parts and labor. Also getting a msg on info screen 'connected device not supported' now. Apparently toyota did an update and there was a bug in the program yet I have to pay to fix their error to the dcm.
NHTSA complaint #11724036 — an unverified report by a vehicle owner.
The slave cylinder failed l3aving me stranded in a parking lot. Luckily I wasnt driving down the highway as the slave cylinder is also part of the brake system they use the shared brake fluid reservoir. This is a very common problem and is a 4k plus cost to fix. Not including the time that has to go into fighting the warranty companies and dealers.
NHTSA complaint #11721047 — an unverified report by a vehicle owner.
“Engine Maintenance Required, See your dealer” light comes on the dashboard with a warning bell. Did a diagnostic test, and the code is the coolant bypass valve malfunction. This seems to be a common issue among 2020-2021 models. This has been inspected by professional mechanics.
NHTSA complaint #11712005 — an unverified report by a vehicle owner.
Dear National Highway Traffic Safety Administration, I am submitting this email to formally report a potential vehicle safety defect involving my 2022 Toyota Corolla. Vehicle information: - Make/Model: 2022 Toyota Corolla - In-service date: 08/18/2022 My vehicle sustained significant wiring damage caused by rodents. Toyota has denied warranty and financial assistance, characterizing the issue as an “outside influence.” However, according to what I read online, modern vehicles —including Toyota models—use soy-based or bio-based wiring insulation, which is widely documented to attract rodents. The damage affected critical electrical wiring, creating potential safety hazards including loss of vehicle function and increased fire risk. This is not merely cosmetic damage but impacts essential vehicle systems. The foreseeability of rodent attraction due to wiring materials raises concerns of a design-related safety defect and failure to adequately warn consumers. Toyota has stated there are no recalls or customer support programs addressing this issue, despite recurring reports from vehicle owners nationwide. I respectfully request that NHTSA review this matter as a potential safety defect and consider whether further investigation is warranted. Thank you for your attention to this safety concern. Sincerely,
NHTSA complaint #11707308 — an unverified report by a vehicle owner.