2024 Honda Prologue: brakes engage by themselves (phantom braking)

Filed Sep 15, 2026 · Driver assistance, Electrical · CA

This car has a problem with the emergency brake system activating when there is nothing in any danger zone. We have owned this car for about a year, and when slowly reversing, we have been repeatedly annoyed by the warning lights & sounds going off & emergency brakes locking the wheels. Each time we check the cameras, mirrors and even get out of the car to look, but there was nothing anywhere near that would trigger such an event. This happened 4-5 times over the past year, and we assumed this was just an ultra-sensitive feature which was annoying and startling when it happened, but generally harmless. Until a similar issue with the brake system happened recently while we were coming to a stop while driving forward, except this time after the warnings went off and brakes locked, the car then shot forward, with my foot still on the brake, and hit the car in front of me. Then it locked up and shot forward again 2 MORE TIMES. I've detailed that event in another complaint on this site, but I wanted to put the original emergency brake problems on the record, in case they end up being related.

Filed Jun 25, 2026 · Driver assistance · CA · crash

Component: Honda Collision Mitigation Braking System (CMBS/AEB). Vehicle is in GEICO insurance claim process, not yet released. EDR data has not been extracted and is available for inspection if preserved before the vehicle changes hands. Safety risk: Two failure modes. (1) False AEB activations occurred multiple times — while driving at ~20 mph and while reversing at low speed, with no obstacle present. Hard sudden braking with no warning created rear-collision risk. (2) On 6/23/2026 at ~9:50 AM, AEB failed to activate when I struck a parked vehicle. Airbags deployed on impact, briefly incapacitating me. My foot remained on the accelerator. Standard post-collision safety design calls for automatic power cutoff and brake application after airbag deployment, specifically to prevent continued acceleration when a driver may be incapacitated. This vehicle did neither — it continued accelerating, significantly worsening the collision. I sustained soreness and bruising. Dealer confirmation: I did not take the vehicle to a dealer for the phantom braking. Per other the federal safety agency complaints for the Prologue and Honda's broader CMBS issues (Engineering Analysis EA25002), dealers have reportedly been unable to replicate the issue and told owners the behavior is normal. Inspections: GEICO assessed the vehicle for the claim. No inspection by Honda or independent mechanic for AEB specifically. EDR data not yet extracted. Warning indicators: During false AEB activations, the collision warning appeared on the dashboard at the moment of braking, not before. No advance warning. No persistent warning lamps or diagnostic messages indicating CMBS malfunction at any point during ownership. Phantom braking occurred intermittently throughout ownership.

Filed Jun 9, 2026 · Brakes, Driver assistance · NM

Description of Safety Defect: The Automatic Emergency Braking (AEB) / Forward Collision Avoidance system is severely malfunctioning. On multiple occasions, the vehicle has experienced "phantom braking"—abruptly slamming on the brakes for no reason whatsoever. There were no obstacles, pedestrians, or vehicles ahead to trigger the system. This malfunction is happening at high speeds on major highways. Safety Risk and Impact: This issue represents an immediate and terrifying safety hazard. Unexpectedly slowing to a sudden stop at highway speeds completely compromises vehicle control and leaves me at an extreme risk of being rear-ended by high-speed traffic. It is a severe danger to myself, my passengers, and every other driver on the road. While the vehicle is currently subject to a manufacturer recall regarding the backup camera and other software updates, this specific, dangerous braking behavior makes the vehicle incredibly unsafe to operate. I request that the federal safety agency review this issue immediately to determine if a broader safety investigation or expanded recall is required for the 2024 Honda Prologue.

Filed Dec 26, 2025 · Driver assistance · CA

The system does not reliably "see" pedestrians or cross traffic or often times will phantom brake when there are no obstacles viewable. I believe this is a substantial safety issue because the car will abruptly stop without warning and engage a parking brake, creating a delay before being able to vacate traffic. This has happened going forward, but more frequently in reverse. This appears to happen more during inclement weather or in the dark.

Filed Dec 17, 2025 · Driver assistance · WA

The parking collision warning will alert and emergency brake for no reason while still several feet from anything near the Prologue. This was demonstrated for and confirmed by the dealership. Then they shrugged and said that Honda has not issued a fix for the problem. This is a safety issue because the sudden emergency brake has nearly caused collisions and has covered me in scalding coffee multiple times.

Filed Jun 30, 2025 · Brakes, Driver assistance · CA

While driving my 2024 Honda Prologue, the automatic emergency braking system (part of Honda's Collision Mitigation Braking System) has activated unexpectedly and forcefully multiple times — with no obstacle or vehicle ahead. The most serious incident occurred on 6/28/2024, while traveling at approximately 70 mph. The vehicle suddenly slammed on the brakes without warning or any visible threat in the road. We did not crash, but the vehicle behind us narrowly avoided rear-ending us. This also happens about 50% of the time we reverse the vehicle. Given the potential severity of this defect — especially involving passenger injuries and potential crashes — I am deeply concerned. Many other Honda owners have reported similar phantom braking behavior across multiple models, and I believe this defect needs to be investigated urgently by the federal safety agency. Honda has not issued a recall or provided public guidance on how to disable or address the system, leaving drivers at risk.

Filed Jun 26, 2025 · Brakes, Driver assistance · CA · 4 injuries

While driving my 2024 Honda Prologue, the automatic emergency braking system (part of Honda's Collision Mitigation Braking System) has activated unexpectedly and forcefully multiple times — with no obstacle or vehicle ahead. The most serious incident occurred on [insert date], while traveling at approximately [insert speed] mph. The vehicle suddenly slammed on the brakes without warning or any visible threat in the road. The sudden stop caused whiplash injuries to my wife and two children, who were passengers in the vehicle. We did not crash, but the vehicle behind us narrowly avoided rear-ending us. I have attempted to get the vehicle serviced, but the nearest dealership told me there is a wait time of over a month, so no diagnostic has yet been performed. Given the potential severity of this defect — especially involving passenger injuries and potential crashes — I am deeply concerned. Many other Honda owners have reported similar phantom braking behavior across multiple models, and I believe this defect needs to be investigated urgently by the federal safety agency. Honda has not issued a recall or provided public guidance on how to disable or address the system, leaving drivers at risk.

Filed Jun 4, 2025 · Brakes, Driver assistance · GA

Driving in the express lanes south of Atlanta in the rain, the vehicle's Automatic Emergency Braking system activated for no reason. There were no other vehicles around, and we were on a straightaway. It was such an abrupt deceleration that if another vehicle had been tailgating me, they probably would have run into me.

Filed May 28, 2025 · Body, Brakes · NC

When I was taking my Prologue in reverse and will slam on the brakes even when there is nothing behind me. It happens frequently nothing behind me. As others have reported here and elsewhere online, my Prologue emergency braking/collision detection system repeatedly activates when there is no danger of a collision. Backing out of my driveway I can expect that 40% of the time the car will slam on the brakes for no reason and apply the parking brake, which I then have to disengage manually to continue backing out.

Filed Feb 21, 2025 · Brakes, Driver assistance · CA

Braking for no reason slam on the breaks so hard we all got so scare. Also the rear brakes engaging with no obstacles on the way.it felts like I hit something. took to the the dealer of purchase and very much make me field like I was insane. and what the technician did was turning off the automatic breaking system. that was the solution. now at when I turn right of left it makes a ticking noise on the suspension. started at 4k miles. plus a win noise is so heavy that I need to the radio volume. I got this car because of the automatic breaking technology offer, but I can't utilize it do to the failure of the system.

Filed Feb 5, 2025 · Driver assistance, Suspension · ME

As others have reported here and elsewhere online, my Prologue emergency braking/collision detection system repeatedly activates when there is no danger of a collision. Backing out of my driveway I can expect that 25-50% of the time the car will slam on the brakes for no reason and apply the parking brake, which I then have to disengage manually to continue backing out. More recently, I was driving 30 mph on a city street with no one in front of me when without warning the Prologue slammed to a complete stop. Fortunately no one was behind me or I almost certainly would have been rear-ended. After four months of owning the Prologue, and seeing this exact problem reported over and over again, it's evident the entire electronics system is glitchy at best and downright dangerous at worst. Everything from the crash-avoidance cameras (regularly issues messages that they're blocked when they're obviously not) to the remote starter (supposed to come on with two quick presses of a button on the fob, but often takes a dozen or more to actually activate) is borderline non-functional. Whether this is a software or a hardware problem, or some combination thereof, there's no question in my mind that sooner or later, as more of these vehicles are on the road, one of these malfunctions is going to cause a crash. I hope the federal safety agency will see enough of a quorum of similar complaints to investigate before that happens. For my part, I've turned off all driver assist systems in my Prologue, which is the only way I can be assured the car will only brake when it should. Additionally, again as many others have reported, my Prologue knocks somewhere in the vicinity of the front axle whenever I corner sharply enough in either direction.

Filed Feb 3, 2025 · Driver assistance, Steering · WA

when turn i hear a clicking sound dealer technician acknowledges sound but refuses to repair. forward collision system sees things that are not there and slams on the brakes for no reason. hvac system fails to heat until after driving for at least 45 minutes even after pre heating.