2018 Honda Accord Hybrid

On February 21, 2022, the Office of Defects Investigation (ODI) opened Preliminary Evaluation (PE22003) to assess reports of inadvertent activation of the Collision Mitigation Braking System (CMBS), an automatic emergency braking (AEB) system, in model year 2017-2019 Honda CR-V and 2018-2019 Honda Accord vehicles.  The reports allege that activation of the AEB system occurs while driving with no apparent obstruction in the vehicle's forward path, resulting in sudden vehicle deceleration. Honda indicated that they were aware of a total of X,XXX reports that may relate to the alleged defect. Honda provided analysis of the alleged defect and alleges that some customers possibly had an inadequate understanding of the CMBS and its limitations.  However, many consumer complaints allege that Honda dealerships were unable to reproduce the condition or state that they were informed that this is considered normal CMBS operation. To date, ODI has received a total of 1,294 consumer complaints of inadvertent activation of CMBS in 2017-2022 Honda CR-V and 2018-2022 Honda Accord vehicles. A total of 31 complaints alleged a crash and 50 alleged an injury.  The Total column in the Failure Report Summary removes duplicate reports and shows the total number of reports with unique VINs from all Manufacturer, ODI, and EWR data sources.  In some cases, there were multiple reports associated with a particular vehicle in which recurring failures were alleged.  In total, there were X,XXX reports, 93 injury incidents and 47 crashes involving vehicles with unique VINs that may relate to the alleged defect. PE22-003 has been upgraded to an Engineering Analysis to further assess the scope, frequency, and potential safety related consequences of the inadvertent AEB activations. The scope has been expanded to include assessment of model year 2020-2022 Honda CR-V and Accord vehicles. To review the ODI reports cited in the Opening Resume ODI Report Identification Number document, go to NHTSA.gov.

NHTSA received a petition on or about July 18, 2022, requesting that Federal Motor Vehicle Safety Standard (FMVSS) 141 be applied to all electric and hybrid vehicles operating in the United States. The petition can be reviewed at NHTSA.gov under ODI Number 11486072. FMVSS 141 establishes performance requirements for pedestrian alert sounds for motor vehicles. The standard applies to hybrid and electric vehicles that have a gross vehicle weight rating of 4,536 KG or less or are defined as low-speed vehicles. The standard became fully applicable to all such vehicles manufactured on or after March 1, 2021.On January 27, 2023, NHTSA opened Defect Petition (DP) 22-005 to evaluate the subject matter described in the petition. On June 24, 2023 and as supplemented on June 25, 2023, the petitioner notified NHTSA he was withdrawing his petition. The petitioner indicated that, based on his review of data, there is no justification for asserting potential benefits that could be derived from actions sought by my petition. Based on the petitioner's withdrawal, DP22-005 is closed. Closure of this DP does not represent a determination by NHTSA regarding the subject matter of the petition.

On February 21, 2022, the Office of Defects Investigation (ODI) opened Preliminary Evaluation (PE22003) to assess reports of inadvertent activation of the Collision Mitigation Braking System (CMBS), an automatic emergency braking (AEB) system, in model year 2017-2019 Honda CR-V and 2018-2019 Honda Accord vehicles.  The reports allege that activation of the AEB system occurs while driving with no apparent obstruction in the vehicle's forward path, resulting in sudden vehicle deceleration. Honda indicated that they were aware of a total of X,XXX reports that may relate to the alleged defect. Honda provided analysis of the alleged defect and alleges that some customers possibly had an inadequate understanding of the CMBS and its limitations.  However, many consumer complaints allege that Honda dealerships were unable to reproduce the condition or state that they were informed that this is considered normal CMBS operation. To date, ODI has received a total of 1,081 consumer complaints of inadvertent activation of CMBS in the subject vehicles.  A total of 24 complaints alleged a crash and 42 alleged an injury.  The Total column in the Failure Report Summary removes duplicate reports and shows the total number of reports with unique VINs from all Manufacturer, ODI, and EWR data sources.  In some cases, there were multiple reports associated with a particular vehicle in which recurring failures were alleged.  In total, there were X,XXX reports, 84 injury incidents and 40 crashes involving vehicles with unique VINs that may relate to the alleged defect. PE22003 has been upgraded to an Engineering Analysis (EA24002) to further assess the scope, frequency, and potential safety related consequences of the inadvertent AEB activations.  Further the scope has been expanded to include assessment of model year 2020-2022 Honda CR-V and Accord vehicles. To review the ODI reports cited in the Opening Resume ODI Report Identification Number document, go to NHTSA.gov.

On 2-252026 my wife and I were driving on highway I-15 in California when the car started to accelerate, decelerate and jerk and the engine light came on. It was very scary because we were on a major highway driving around 60 MPH and cars were behind us when the deceleration happened. We could have been hit by cars traveling behind us or either we could have caused a major accident. We had to get off the highway and have the car towed to Honda for assessment. There was no engine light warning or service warning from Honda prior to this happening, it just randomly happened. The car was repaired at a Honda dealership and they said there was a leaking head gasket on cylinder number 4. When we looked up information regarding this head gasket failure we saw that other Honda cars have had the same problem and Honda is currently involved in lawsuits regarding this leaking head gasket on cylinder number 4.

NHTSA ID

11746562

Incident

Feb 25, 2026

While driving on the highway at approximately 65 mph with my child in the vehicle during rush-hour on May 21, 2026, my 2018 Honda Accord Hybrid Touring (105,746 miles) suddenly dropped speed, and began backfiring and stopped responding to the gas pedal. The check engine light flashed and the vehicle ran rough. I activated emergency flashers and drove slowly to the shoulder. Sunnyvale Honda (Sunnyvale, CA) diagnosed coolant intrusion into one of the cylinders and head gasket failure. The vehicle had never overheated and showed no prior warning signs. All maintenance was performed at Honda dealerships per the maintenance minder schedule. The dealership performed a head gasket repair costing $7,500+ out of pocket. On the first highway drive after pickup, again with my children in the vehicle, the identical failure occurred: backfiring, complete loss of throttle response, vehicle unable to exceed 48 mph with the accelerator fully depressed. The repair did not resolve the defect. The vehicle is currently back at the dealership for further investigation. This failure created an immediate safety hazard on both occasions: sudden loss of speed on highway with no warning. Honda Customer Service denied goodwill assistance. I am aware of numerous similar complaints involving coolant leak and head gasket failure on 2018-2022 Accord including complaints documenting the same failure on the Accord Hybrid 2.0L engine. NHTSA should investigate this as a potential safety-related defect affecting multiple Honda engine variants.

NHTSA ID

11746305

Incident

May 21, 2026

Over the past several years, there have been multiple instances where I or my wife are driving on the highway and the engine light comes on or starts flashing, and I am unable to go faster than 50 miles an hour, and the engine itself feels to be underpowered. We have taken it to the dealership for repair at least five times over the past five years and in each case they have attempted to do a repair and said the issue has been resolved, but the issue continue. At at least one of those visits, they have diagnosed the issue as an engine misfire issue. The issue has intensified from the initial symptoms, (which were as I described, but resolved by turning the car off, waiting 30 seconds to a minute and then turning the car on again) to how it is now: in addition to the check engine light, every other light and warning system has gone off when driving on the highway and the engine was unable to go faster than 40 miles an hour, and it does not resolve by restarting the car. The dealership and Honda America’s main phone line have as of yet been unable to give me a clear answer as to why this is happening or whether it can be fixed. A sudden drop in speed and power on the highway as we have experienced many times over the last five years is inherently extremely dangerous.

NHTSA ID

11715485

Incident

Jan 31, 2026

The car loses power. It starts as a misfire on cylinder 2 (P0302 code) and the engine starts to shutdown (or goes into a safe mode with no power). The result is loss of speed which creates a safety hazard especially on highways. This has happened multiple times and the car has been in the shop 4 times for this issue. We have to pull off the road, turn the car off, sit for a minute and restart the car. It will then run ok. This has happened during acceleration and when just trying to keep speed on an incline. The dealership has not been able to identify an issue. The head gasket was replaced in April 2025 because they thought there was a pin hole that was causing oil to push into the cylinder. The misfire continued to happen. It was in the shop on October 2025 and they found nothing wrong with the spark plug, induction coils, gas feed. Therefore no understanding of the root cause.

NHTSA ID

11693248

Incident

Oct 2, 2023

The contact owns a 2018 Honda Accord. The contact stated that upon starting the vehicle, various warning lights were illuminated. The contact stated that the Lane Departure, Lane Keep Assist, ACC, and Blind Spot Detection warning lights remained illuminated. The vehicle was taken to a local dealer, where it was diagnosed, and the contact was informed that the malfunction or warning lights were a result of the camera being faulty and that the camera needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 105,000.

NHTSA ID

11686086

Incident

Sep 9, 2025

Mileage

105,000 mi

The engine head gasket failed due to design flows. I have to put coolants and oil on a daily basis to keep the car running to avoid overheating.

NHTSA ID

11683633

Incident

Aug 27, 2025

At approximately [XXX]. Pacific, I was traveling southbound in the fastrak lane of the [XXX] departing from Pleasant Hill, California headed to Pleasanton, California. As I began to accelerate, the engine began to sputter. Immediately, the check engine light flashed on, then the dashboard reported a number of issues ranging from brake failure, TPMS failure, power assisted steering failure, vehicle stability assist failure and a number of other issues that I have never encountered since purchasing the vehicle. The sudden deceleration almost resulted in other cars impacting my car as this occurred during the morning commute. I was able to safely navigate off of the freeway. I was on speakerphone with Honda when this occurred. Had I not acted swiftly, a potential high speed rear end collision was likely to have occurred. I immediately took the car to Concord Honda. The team at Concord Honda performed a diagnosis and advised me that my head gasket was leaking water into the combustion chamber which resulted in the sudden loss of power. I was and continue to be dissatisfied with the handling of this issue by Honda as my car has never been handled by another mechanic. My car has a perfect or near perfect maintenance record and should not have a blown head gasket at 80k miles especially since my car is meticulously maintained and serviced by Concord Honda. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11679970

Incident

Aug 11, 2025

when i am driving in an area near my home with road construction- there is a certain area that has a metal plate in the road and when i approach in from the east my car will automatically brake hard. luckily this has not caused an accident but i suspect that it may because it is a busy road.

NHTSA ID

11668985

Incident

Jun 24, 2025

Service Bulletin - Honda has developed software updates to the Honda Sensing system to enhance driver experience by modifying the circumstances when the advanced driver assist system (ADAS) decelerates the vehicle or the extent of deceleration. The software covers Adaptive Cruise Control (ACC), Collision Mitigation Braking System (CMBS), and Road Departure Mitigation (RDM).

Service Bulletin - American Honda has identified a condition that may affect Collision Mitigation Braking System (CMBS) operation. Due to software programming issues of the Advanced Driver Assistance System (ADAS), unexpected vehicle deceleration may occur.

Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2018-2022 Accord FHEVs with a customer complaint of the Malfunction Indicator Light (MIL) on with the DTC P030X (Cylinder Misfire Detected) stored. Customer may also experience engine running rough condition. To better understand the cause of this condition, AHM would like to collect specific parts from the vehicle prior to you attempting a repair of any kind.

Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2018-2022 Accord FHEVs & 2020-2022 CR-V FHEVs with a customer complaint of the Malfunction Indicator Light (MIL) on with the DTC P030X (Cylinder Misfire Detected) stored. Customer may also experience engine running rough condition. To better understand the cause of this condition, AHM would like to collect specific parts from the vehicle prior to you attempting a repair of any kind.

Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2018-2022 Accord FHEVs & 2020-2022 CR-V FHEVs with a customer complaint of the Malfunction Indicator Light (MIL) on with the DTC P030X (Cylinder Misfire Detected) stored. Customer may also experience engine running rough condition. To better understand the cause of this condition, AHM would like to collect specific parts from the vehicle prior to you attempting a repair of any kind.

Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2018-2022 Accord FHEVs & 2020-2022 CR-V FHEVs with a customer complaint of the Malfunction Indicator Light (MIL) on with the DTC P030X (Cylinder Misfire Detected) stored. Customer may also experience engine running rough condition. To better understand the cause of this condition, AHM would like to collect specific parts from the vehicle prior to you attempting a repair of any kind.