2021 Honda Odyssey Collision Avoidance Problems

Your forward collision avoidance system is braking unexpectedly when there's nothing in front of your car, and it's also triggering the lane departure warning in construction zones where temporary lane lines replace permanent ones. This causes your car to brake hard and come to a stop in the middle of the highway, creating a dangerous situation. The fix would likely involve updating the safety system's software or recalibrating its sensors to better distinguish between real obstacles and false triggers.

Your van's forward collision avoidance system is braking hard without any cars or obstacles in front of you — sometimes triggered by metal plates or speed bumps on the ground, but often with nothing visible ahead. When this happens, you can't override the brakes by pressing the gas pedal, which creates a dangerous situation where vehicles behind you might rear-end you. This occurs most frequently during school pickup and dropoff times, and your dealer hasn't been able to find or reproduce the problem. The fix will likely involve diagnosing and recalibrating the forward-facing camera or radar sensors that control the collision avoidance system.

I was driving in light snowfall when several alerts notifying me that the radar sensor was not working. This is common in snow fall. Later I cleared off the radar unit cover (The Honda logo on the front of the car). The alerts remained. I took it to the dealer and they dubiously told me it was "damaged by snow". This is impossible. It was light snow. There was no collision or impact. This device should be durable. It has no moving parts. But Honda wants me to believe that it simply stopped working from driving in a light snow. They want $1300 to replace. How do I know the next one won't conk out after the first snowfall? These units should have a lifetime warranty with only exceptions for collisions or impact damage. If the unit is damaged by snowfall, it's clearly too fragile and should not be on the market. It's a HUGE safety concern that the vehicle's advertised safety systems can be toppled like a house of cards from one light snowfall.

The children message that the radar is obstructed, I did the clean where is the radar is but the issue still.

After a slight rain, the error of Radar Obstructed is being displayed. Can’t get this error removed or fixed. After searching more I found out that: 1. Honda has a defective design in the Advanced Driver Assistance Systems (ADAS) of all Honda Odysseys, models 2018-2023. 2. Namely, Honda has placed the RADAR behind the large HONDA emblem on the front grille. This causes the radar to give a "RADAR OBSTRUCTED" warning, which disables all Advanced Driver Assistance Systems in the car (Automatic Emergency Braking, Adaptive Cruise Control, Forward Collision Warning). 3. The "RADAR OBSTRUCTED" warning cannot be reset by restarting the vehicle or disconnecting the battery, requiring recalibration of the RADAR at the cost of $800 each time since it takes several hours to do (per Dealership). 4. The official Honda Odyssey Forum online has countless complaints on the same issue without resolution by Honda. 5. Honda has acted in bad-faith towards their customers since this defect impacts the vehicle's advanced safety features for which buyers incur additional expenses, endangering the lives of passengers. 6. Honda has acted in bad-faith towards their customers by designing a system that requires continuous and substantial expenditures without resolution because it is an engineering problem, i.e., the placement of the radar behind the large, thick plastic H emblem obstructs the radar. 7. I hereby ask that the NHTSA investigate this issue and order Honda to offer a solution in the form of a RECALL that permanently addresses the problem.

I am writing to urgently bring to your attention a critical issue plaguing the driver assist systems in Honda Odyssey 2018+ vehicles. Despite meticulous maintenance and adherence to manufacturer guidelines, I have encountered a persistent and alarming problem that appears to affect numerous other vehicle owners, as evidenced by online forums and discussions. The issue initially arose during a rainstorm, where I received a warning message stating, "Some Driver Assist Systems Cannot Operate: Radar Obstructed." Despite the weather clearing and thorough cleaning of both the sensors and the windshield camera, the warning persisted. Subsequently, a series of related problems emerged, including: Illumination of the BRAKE SYSTEM LIGHT Malfunctioning adaptive cruise control Faulty collision mitigation system Inoperative road departure mitigation system These errors not only pose a significant safety risk to myself and others on the road but also indicate a systemic issue with the vehicle's safety systems. As my vehicle is just past the three-year mark and out of warranty, I am apprehensive about incurring substantial costs for dealership repairs, especially considering the widespread nature of these complaints among Honda Odyssey owners. Extensive research reveals that I am not alone in experiencing these issues. Multiple reports and discussions online highlight similar complaints from other Honda Odyssey 2018+ owners, particularly following exposure to adverse weather conditions. Therefore, I implore the National Highway Traffic Safety Administration to conduct a thorough investigation into this matter. It is crucial to identify the underlying cause of these recurring issues and hold the manufacturer accountable for any design flaws or defects contributing to the malfunction of critical safety systems. Furthermore, I urge NHTSA to prioritize public safety and take immediate action to ensure affected vehicles are promptly recalled or repaired to prevent further incident

I was driving through an intersection. My automatic brakes activated for no reason, my car rapidly slowed down in the middle of an intersection, a bus hit my car from behind.

While driving on a straight, wide open road at approximately 45mph with no vehicle in any close proximity in front, the forward Collision Mitigation Braking System alarmed and activated and strongly braked, slowing the car quickly down to about 20mph before releasing. Fortunately, there was no one behind me to react to the unexpected slowing down of my car. There was no apparent reason why this should have activated. The CMBS has activated previously in other non-threatening situations but there was usually a condition where you could justify why it made a mistake, such as being in the left lane of a two lane road which curves to the left and a car in the right lane slows to turn right, my car thinks it is in front of me when it is not. Still, these situations result in a danger of getting hit from behind.

Exiting a construction zone (I-70 westbound near Mt. Comfort, Indiana) at approximately 60 to 65 mph, our 2021 Honda Odyssey, without warning, momentarily applied unwarranted automatic emergency braking. The brakes were actuated for (an estimated) one second and resulted in an abrupt (approximately) 10mph reduction in speed. A large SUV traveling directly us was forced to take immediate action by making a sudden lane change in order to avoid a serious collision. The involuntary braking action on the part of the vehicle placed the passengers of both vehicles in grave danger. The only warning indication provided by the vehicle was an orange-box “BRAKE” warning displayed on the dashboard and the accompanying warning beeps, both simultaneous to the actual brake actuation. No indications or warnings appeared prior to or after the actual braking. No obstacle or object on the roadway was visible to either the driver or front seat passenger. All traffic lanes were clear for a minimum of 100 yards ahead of the vehicle. Weather was clear and dry. The pavement was dry and clear of any debris. The construction zone where the incident occurred carries both east and westbound traffic on the normally westbound (north) side of the expressway. The left side of the traffic lanes are lined with continuous, concrete “Jersey” barriers. The incident took place at the western end of the zone, at the point where the westbound lanes expand from two to three lanes. This is approximately where the left-side parallel-to-traffic barriers end and a small, separated section of angled-to-traffic barriers is revealed, along with some other barrier sections in the median area between the roadways. This incident (November 26, 2022) was the second time this malfunction has occurred in same vehicle in approximately the same area on I-70. On August 11, 2022, an essentially identical event took place under similar conditions. The vehicle has not been inspected by Honda or any other authorities.

On numerous occasions the forward collision warning has caused hard braking when there is nothing close in front of me. I fear that a close following vehicle will hit me when this occurs. This has not caused an accident yet, but the following vehicle driver must think that I'm a terrible driver for unnecessarily hitting my brakes.

While driving with no vehicles or obstacles stopped in front of me, my car automatically braked hard.