What 403 owners told NHTSA about the 2024 Mazda Cx-90-phev

I am reporting a safety problem with the adaptive cruise control feature of my 2023 Mazda CX-90. The adaptive cruise control system does not detect the lanes correctly and applies the brakes unnecessarily, even when there are no cars in front of me. This happens especially on curves and when there are trucks on other lanes. This is very dangerous and I have been close to be rear-ended several times. I do not feel safe driving this car with this feature on. I haven't contacted my dealer, but it seems to be a well known issue for many owners. [XXX] [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11557440

When using the adaptive cruise control on a multi-lane highway the system will detect trucks/larger vehicles moving into your lane on a slight curve when they are not. The system will apply brakes to avoid a collision. The first time this happened there was no vehicle moving into my lane but there was an 18-wheeler behind me that wasn't expecting my vehicle to brake and they almost rear-ended me. This happened several other times before I understood the problem and turned the system off. I have reported this to my dealer and they stated the problem couldn't be replicated. This has been reported multiple times by other CX-90 drivers on this site and Mazda will get someone injured or killed if this is not fixed. If you drive a CX-90 do not use the cruise control until this is addressed by Mazda.

NHTSA ODI 11556548

When using adaptive cruise control and you are driving on a curve, if there is a vehicle, guard rail or jersey barrier in the next lane or on the side of the road, the vehicle will brake hard thinking there’s something in front of it. It has even happened when there was a hillside next to the road. This is very dangerous on a high speed highway. It can slow down from 75 mph to 45 mph in a very short amount of time.

NHTSA ODI 11555845

When going into curves on interstate, car thinks its gonna hit something and slams on the brakes when cruise control is engages. When passing a semi (semi slow lane, passing in passing lane), vehicle detects something in front of it and slams on the brakes. Does this on straight stretches. Slows down extremely fast to mabye 40 mph, then floors it once it thinks the "obstacle" has disappeared and speeds back up to the set speed as fast as it can. Sometimes does it when no othwr vehicles near it on straight stretchss of highway. This is gonna cause accidens. I don't trust the adaptive cruise control feature because it does this. This isn't weather or light related. Does it all the time.

NHTSA ODI 11555554

When adaptive cruise control is engaged, and travelling in the left lane of a multilane highway, automatic braking frequently activates when there is a vehicle ahead in the right lane (especially, but not always, a truck) but no hazard in the lane directly ahead.

NHTSA ODI 11555079

While driving on freeway with Adaptive cruise control set, vehicle automatically brakes when passing large vehicles, like semi trucks. ACC set at 75, I'm in left lane to pass truck going around curve and brakes come on and slow vehicle down to 60. I am clearly in the left lane to pass and truck in right lane. My safety and those behind are at a HUGE risk. This will cause an accident if not addressed. I am going to get rearended, it's just a matter of time. I have taken it to dealership and have been told this is normal. No it is not! No warnings other than car slamming on breaks for no reason. This has happened several times. I put down the date it first happened. I am available to bring it to dearship, again.

NHTSA ODI 11554481

Using the adaptive cruise control in I-64, the car will dangerously slow down/brake in the turns. If someone was following m, this slow down would have been unexpected, and could have rear ended us or lost control trying to avoid us. Unexpected slowdowns are dangerous. Not sure if this happens at lower speeds on side triads since I don’t use the cruise control on those roads.

NHTSA ODI 11554483

When operating the radar cruise control, if a large truck (semi, box truck) is next to you when going around a curve, the vehicle is seeing that truck in your lane and applies the brakes very suddenly. This is an issue, because if someone is following behind you, it is almost as if you are brake checking them. Clearly that is not safe at highway speeds. This has happened to me several times since owning this vehicle.

NHTSA ODI 11554501

When driving on a highway with cruise control on. If you are in an outside lane and the is a tractor-trailer in the inside lane maybe 100-200 feet ahead of you. If the highway veers to the left even though the truck remains in the inside lane the system seems to think the truck is right in front of the car. Cruise shuts down and it starts to brake. I have almost gotten hit by cars behind me twice. It has happened 4 times now. The first time was in mid June 2023 and three other times since. I asked about it and was told to go with manual cruise - I would have to manually do that each time I want to use it. Not acceptable and very unsafe. Reports of this type of incident have shown up several times on the Facebook Mazda CX-90 site. One other problem is with the front bushings. A hard right turn going over any kind of bump causes a severe rubbing sound.

NHTSA ODI 11554525

Cruise control safety concern: car detects vehicle in front when there isn't and brakes sometimes hard abruptly due to misdetecting a vehicle ahead in a different lane as is it was in the car's same lane specially in curves or if the vehicle ahead but in a different lane is casting a shadow in front of car. Blind spot: blind spot detects a vehicle in the blind spot even when there's no vehicle. Noticed that car sometimes detects vehicles on an opposite direction road as if they're in the blind spot and it can set off the blind spot monitor.

NHTSA ODI 11554557

While using the radar cruise control, the vehicle will aggressively apply braking pressure, without warning and risk losing control of the vehicle. The risk of being rear ended is frightening at highway speeds. This usually happens through turns, and the Mazda mistakes vehicles in opposite lanes as being in the same lane. This has occurred multiple times with different people.

NHTSA ODI 11554603

When a large object like 18wheeler is in right lane and you are in left lane the car thinks it is in your way and the vehicle brakes hard. Very dangerous. Has happened numerous times.

NHTSA ODI 11554606

This vehicle at highway speeds will suddenly brake when intuitive cruise control is engaged. It mainly does this when the hwy is not straight and there is a vehicle ahead in a different lane or if there is a concrete median on either side. It’s not safe to be going 70-78mph and have your vehicle brake and bring speed down to 50-60. I’ve had intuitive cruise control on 3 other vehicles and none of them did this. Vehicles following become upset when vehicle brakes with no vehicle ahead of us. Also, it’s a danger of being rear ended or causing a road range incident when someone behind you thinks you are brake checking them.

NHTSA ODI 11554294

My car detects a vehicle in front and slows down in the following scenario - when on cruise control and passing a big truck from the other lane and the road is bent toward the right or left. It's so annoying and I might get rear-ended one day as the vehicle behind me doesn't expect that I slow down. Very dangerous safety issue!

NHTSA ODI 11554002

The vehicle incorrectly sensed a large truck in the right lane, next to the lane I was in, as being in my lane causing the vehicle to slam on the brakes and caused me to nearly get rear ended by following vehicle. Other vehicle had no notice, as my lane was completely clear. Further testing on my part found that numerous vehicles had incorrect lane placement on the provided graphical display. Dealer says everything checks out normal. This is a major safety issue for me.

NHTSA ODI 11553904

While traveling in the left lane on a 2 lane interstate, 79S, the car suddenly braked as I passed a truck in the right lane entering a curve. The "apply brake now" emergency message also flashed on the display. Had a vehicle been closely following behind, it would have crashed into my rear

NHTSA ODI 11553428

When using adaptive cruise control and passing a large trailer or truck in the left lane (the trailer or truck is in the right lane), the adaptive cruise control system incorrectly detects the trailer or truck to be in the same lane as the CX-90 and in some situations can slam on the brakes causing a potentially dangerous situation.

NHTSA ODI 11552683

The adaptive cruise control sometimes misreads the driving situation, especially on curves, and applies strong braking when there is no vehicle ahead in your lane. Especially when the vehicle in the adjacent lane is a truck. This could easily lead to being rear ended by a close following vehicle that is not expecting you to abruptly slow down. I had to turn it off on a trip on mountain interstates. I will address this at my first oil change at the dealer. I have had adaptive cruise on several other vehicles and never experienced this problem.

NHTSA ODI 11552392

Hi, When passing a truck which is on the right lane of the car, the car recognise the truck as a car in it's current plane and putting a sudden brakes. I almost got rear ended couple of times in the last one month. Please request Mazda to fix this Adaptive Cruise Control issue. Thanks, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11552064

When ACC is on and speed is set, if the vehicle comes up onto a tractor trailer in the right lane, the CX-90 will think it is actually in front of my vehicle and abruptly slow my vehicle down, potentially causing myself to be rear ended.

NHTSA ODI 11551780

while passing a truck that is in the right hand lane, adaptive cruise control will pick up a vehicle straight ahead and hit the brakes hard. Issue - there is no vehicle in front of you. Almost got rear ended due to this issue.

NHTSA ODI 11551746

Drive on freeway with Mazda Radar Cruise Control engaged. When the road curves slightly, the radar picks up the car in the right lane next to me as a car in front of me and slams the brakes. It’s a dangerous situation when the traffic is moving at least 65 miles per hour.

NHTSA ODI 11551932

The adaptive cruise control (ACC) system in the CX90 is experiencing a high number of false positive incidents, which could lead to accidents. The system consistently thinks that a vehicle in the right or left lane has moved in front of the CX90, mainly when going around a curve. This is especially common when passing 18-wheelers, where the system will start alerting the driver with a noise and flashing alert to depress the brake pedal. The system then begins emergency braking procedures, even though the 18-wheeler or other vehicle has not actually moved lanes. This rapid deceleration at highway speeds is incredibly dangerous, especially for vehicles and large trucks following behind the CX90. In all of my incidents, the system has detected a vehicle in the other lane, but the vehicle has made no deviation towards the CX90's lane.

NHTSA ODI 11551719

When radar cruise control is on, the car sometimes brakes hard totally unexpectedly when it’s about to overtake to a slower-moving vehicle in the adjacent right lane, and despite the fact that the CX-90 does not have any vehicle directly in front of it in its lane. This happens quite regularly at highway, when I am guetting within 100-200 ft of a semi located on the adjacent right lane, even when the road is at right. I almost got rear ended at 75mph by another vehicle because of that, as they did not expect my car to brake while overtaking a semi at that speed with no car in front of me. Very dangerous and needs to be fixed by Mazda.

NHTSA ODI 11551122

During normal driving conditions going down a state highway, the vehicle lost speed with adaptive cruise control enabled. Noticing the vehicle was losing speed, I depressed the accelerator pedal. The accelerator pedal was unresponsive and unable to accelerate, I had to maneuver off the highway. Luckily, the car behind my vehicle was far enough behind me and my vehicle was going fast enough that I was able to coast to a safe stop on the side of the highway. A message popped up on the instrument cluster screen informing me to shift the transmission to Park in order to use the accelerator pedal. If this had happened on a road with little to no shoulder, the vehicle would have come to a sudden stop with nowhere to maneuver to. This would have created a dangerous situation for me, and any vehicle directly behind me. I then parked the vehicle on the side of the highway and with the vehicle still on and engine running, I again tried depressing the accelerator pedal. Again, there was no response from the pedal. I then turned the vehicle off, and restarted the vehicle. I was finally able to use the accelerator pedal and returned to the highway and my drive. The dealership was contacted a few hours after the incident, and the vehicle has yet to be inspected or problem reproduced. The vehicle is a 2024 MY and has been owned for only one month. Unfortunately, this incident is only one of five total electrical issues I have had with this vehicle. This was the most important issue to report because it involved my own safety.

NHTSA ODI 11521778