2021 Acura RDX Driver assistance Problems

On or about XXX, my 2021 Acura RDX, with approximately 121,078 miles, suddenly displayed multiple dashboard warning lights and system-failure messages while I was driving. These included the check-engine light, Road Departure Mitigation System Problem, steering, stability-control, braking-assistance and other driver-assistance warnings. Earlier, the tire-pressure monitoring system had also indicated a malfunction even though the tire pressures were correct. The vehicle initially continued to drive and the conventional brakes appeared to function normally. However, it then began hesitating when I attempted to accelerate. The vehicle would eventually gain speed, but the initial hesitation created a serious safety concern when pulling into traffic or attempting to accelerate. The check-engine light remained solid while the vehicle was stopped but flashed whenever I began driving and accelerating again. No crash, fire or injury occurred. The vehicle had undergone a full diagnostic inspection approximately two weeks earlier, and I was informed that everything checked out properly. There were no known drivability problems before this incident, and the vehicle has been maintained according to the manufacturer’s recommended service schedule. The vehicle was subsequently inspected by Elite Acura, an authorized Acura dealership in [XXX]. The dealership confirmed a head-gasket failure and a problem with the rear differential left-side actuator. The dealer recommended replacing the head gasket, four spark plugs, coolant, oil and filter, as well as replacing the rear differential left-side actuator and changing the differential fluid. The estimated head-gasket repair was $5,391.46, and the estimated rear differential actuator and fluid service was $813.85. The dealer also recommended rear brake pads and rotors. The head-gasket and rear differential actuator problems were confirmed by the authorized Acura dealership. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11750876

Incident

Jul 15, 2026

At start up, my car displayed 4 errors: Lane Keeping Assist System, Collision Mitigation Braking System, Road Departure Mitigation System, and Electric Power Steering. As a result, my car could not steer and had to get it towed to the dealership.

NHTSA ID

11667398

Incident

Jun 16, 2025

Drove into parking lot and as I was pulling into the parking spot next to the building, the vehicle started to surge forward as if I had my foot on the gas instead of the brake. The sudden surge caused the vehicle to plow into a brick building causing about $10K damage to the vehicle and $5K to the building. This was not the first time this sudden surging occurred. It happened at least 3 times previously, and one time since. Fortunately, the other occurrences did not lead to any damages, but just some anxious moments. I took the vehicle to the dealership to get checked out after the last occurrence, but they said they couldn't duplicate it. I thought it might be some sort of "unknown" problem, until I started reading on Facebook and other internet websites of other people having the same scary "surging" engine issues. I believe there's more to it now, and an investigation is warranted.

NHTSA ID

11665825

Incident

May 22, 2024

While accelerating off the entrance ramp onto the highway, The engine randomly slows down automatically…the car reduced speed drastically without applying brakes and without cars around me or in front of me.

NHTSA ID

11639766

Incident

Jan 28, 2025

On 2-10-2024 I was driving the 2021 RDX SH-AWD on I-40W in TN with my daughter in the passenger's seat. It was raining. After about 2 hours of driving, at about 3:00 pm, I took a break at a Rest Area near Buffalo Valley. After ~20-min rest, I restarted the car and tried to merge back onto I-40W. I was accelerating towards the speed limit of 70 m/h, but suddenly, at about 65m/h, I felt the car losing power. I could not speed up anymore: the car did not respond to the gas pedal and the speed dropped to about 40m/h. The orange engine light started to flash on the dashboard. A truck nearly piled on me from behind. Cars and trucks from behind had to switch lanes quickly to avoid collision. I was able to pull over to the shoulder and stopped with my emergency light on. I turned off the engine for about 10 minutes, then I restarted the car again and got back on the road. This time, everything seemed normal, but I was so scared and worried the car might suddenly not respond again. Fortunately, I was able to get home eventually without any additional problems.

NHTSA ID

11575647

Incident

Feb 10, 2024

On 12/22/22, I was driving in a 2021 RDX SH-AWD with my pregnant wife and 2 year old son from Media PA to Pittsburgh PA . It was rainy and 35-40 degrees F the whole drive. Approximately 4 hours into the drive we stopped at a rest stop on the PA turnpike to get gas. While attempting to merge back onto the turnpike from the service road to the right of the turnpike, a truck was coming up behind me in the right hand lane of the turnpike. I was traveling approximately 40mph on the service road, so I went to accelerate to safely complete the merge in front of the truck. Near the end of my acceleration sequence (I estimate I had gotten to approx 65mph) my car went into “limp mode”. I felt an unexpected and immediate loss of power and my check engine light/“MIL” began flashing yellow. I was luckily able to barely avoid a collision with the truck that was approaching. After the light started flashing I was unable to turn the knob to switch drive modes (it was in snow mode at the time this all happened). I was unable to do anything but attempt to drive to safety with severe power loss. I was able to coast my car with minimal accelerator response to the next exit off the turnpike and into a motel parking lot. I shut down the car and then turned it back on. When I turned it back on, the MIL light was no longer flashing and I had normal power restored to the vehicle, but interestingly the auto stop/start feature no longer worked. I was able to drive the remainder of the way to Pittsburgh without any further loss in power, though I was anxious the entire drive considering the major malfunction I had just experienced while attempting a merge at highway speeds. The vehicle only had approx 10,500 miles on it at the time of the incident. The vehicle is currently at the dealership being diagnosed. A case has also been opened directly with Acura/Honda.

NHTSA ID

11499336

Incident

Dec 22, 2022

What component or system failed or malfunctioned? Car automatically applied brakes on several occasions, despite no obstacles in front of the car. Incident 1: While driving through an 3-way intersection, the car slammed on the brakes automatically. There was a van in the opposite lane waiting to turn left. There was 2-3 feet of space so there was no risk of collision, but the car slammed on the brakes causing me to come to a sudden stop in the middle of the intersection. Incident 2: I was changing lanes to go past a stopped car in the left lane (It was waiting to make a left turn) The car automatically applied brakes, even though I would not have hit the car. Cars behind me had to slam on their brakes to avoid rear-ending my stopped car. Incident 3: While driving on a freeway at 65 mph with light traffic and no cars in front for at least 1000 ft the car flashed the automatic brake warning. It did not actually apply the brakes, but could have caused an accident considering the speed. Incident 4: While driving on a 2-lane road with cars parked on the sides of the road, the car displayed an automatic brake warning despite no collision being imminent. Incident 5: While driving down a suburban street with no trees or obstacles in sight, the automatic brake warning flashed. How was safety put at risk? Sudden stopping in a road, highway, or intersection could cause an accident. I am concerned for my safety, because if the car stops unexpectedly in the middle of the road, other cars may hit me. This is the same system used in some Hondas, so a recall of Honda vehicles may need to be extended to Acura vehicles. Has the problem been confirmed by dealer? Yes. The service advisor told me that his car has the same problem, but that it is normal and there is nothing they can do about it. Were there any warnings? Usually happens when there is a radar reflective object above or off to the side of the path of travel. The BRAKE warning appears when automatic braking is applied.

NHTSA ID

11481593

Incident

Jan 18, 2022

All software systems failed, disabling the vehicle. Error messages included failure in braking, steering, and other vital systems. Acura roadside assistance determined that the car had to be towed to the nearest dealer. The dealer confirmed the issue was a "DTC P061B PCM internal malfunction" and performed a "PGM-FI software update to correct the issue." The vehicle was completely disabled, and we were 4 1/2 hours from the nearest dealership. There were no warnings or communications prior to the incident.

NHTSA ID

11478200

Incident

Jul 12, 2022

My experience is in the attached file. My concern is Honda (Acura, same company) issued a service bulletin with VIN ranges (which my vehicle falls in) and yet there is no diagnostic error code to show it happened to the car, repair persons/dealerships can and have denied fixing anything because they can’t diagnose it and it’s in the owner’s manual directing the owner to take it to the dealer for repair. That’s a big disconnect. Luckily, I was able to dig to find the bulletin and provided it to my dealer with the description of what happened and they’re going to fix it. But that doesn’t help anyone else. You really should put pressure on American Honda Motor to issue a recall and do it right.

NHTSA ID

11477191

Incident

Jul 17, 2022

One week ago 6-20-22, my car started to ‘chug’ and slow down as I was accelerating up a hill on a highway. It was almost as if my car was losing power. When this happened about 10 warnings signs came up on my dash. I drove it directly to the dealership. They replaced my oil saying the pressure was low. All was well for the day after 6-21 when driving it home from dealership. On 6-22 I went to merge onto a local highway from a stop sign with traffic coming at 55-65 mph. My car would not accelerate over 25 and I was unable to pull of. Thankfully I pulled off onto the next exit. I could have easily been rear ended and hurt. This issue since will go away if I shut off my car and turn it back on, but not every time. It is still chugging and losing power when I drive and all the errors on the dashboard are coming up randomly. I drive A LOT everyday for work and this problem is really scaring me knowing I or others could get hurt.

NHTSA ID

11471260

Incident

Jun 20, 2022

Purchased my 2021 in November of 2020. Two weeks after, i was driving with adaptive cruise on at 65 mph on a freeway. 100 yds ahead i could see a diesel going slower than i, so i looked and saw no one coming at all, so i moved over to the passing lane. I got 5 feet into the lane and the car slammed on its brakes, on its own!!! Thank god no one was behind me or i might have died!! I reported this to Acura within 1 week, and then reported it to DOT the next week. I own one of the first 2021 s made, so i didn’t see a lot of feedback. Now after a year and a half i get on the DOT website and see many complaints like mine. This has happens to me maybe once every 3 weeks. Why has the DOT done nothing about this??!!! Also the DOT says there are no recalls on my car but if you go to the Acura website it says my car is under recall for a driveshaft problem, of which i never received a notice. Why does the DOT exist??

NHTSA ID

11459605

Incident

Nov 10, 2020

I own a 2021 Acura RDX that was purchased new in February 2021. In the 11,500 miles I have driven it, there have been zero problems until yesterday. However, yesterday, when driving on an Interstate highway at 70 mph, in the rain, while passing a semi truck, my Acura RDX suddenly went into limp mode and the check engine light began flashing. After pulling over to the berm, and driving in the limp mode to the next exit, I turned the engine off. When I turned the engine back on it functioned normally and the check engine light went out. The engine has functioned normally for the approximately 100 miles I have driven since that time. Since there is no problem now, I have not taken the vehicle to the dealer to be checked since I felt that they would find nothing. When looking up this problem I found that mine is not an isolated case, and this same thing has happened to other Acura RDX owners. For that reason I am reporting the problem. I have also written to Acura to tell them of the problem. This was a very scary situation to have the engine suddenly, and without warning, go into limp mode while on a busy Interstate highway. Fortunately, in this case I was able to safely get to the berm of the road, but that might not always be possible. I have no idea when this might happen again, which is also scary. It is also very strange that by turning the engine off and then back on the problem disappeared. If requested, I would be happy to have Acura look at my vehicle if it would help to find the root cause of this problem. Thank you for your review of this problem.

NHTSA ID

11434152

Incident

Sep 22, 2021

On 3 separate occasions my Collision mitigation braking system has malfunctioned. The first time I was driving at 55 with my cruise control set with no cars in front, behind or beside me when, without warning or reason, the orange brake light abruptly flashed on my front dash panel and my car abruptly stopped in a whiplash manner. The second occasion I was driving on the interstate at 65, on this particular interstate, the 64, it splits to the right to a separate interstate, the 264, and cars wait until the last minute to go 3 lanes of traffic over to get off. My car again without warning or reason flashed the orange brake sign on my front dash panel and my car abruptly stopped. Thankfully the cars rushing over did not hit me but there were honks and swerves and I could have been hit or caused an accident. The third incident occurred 8/25/21 with my son in the car while the feature was disabled, I was not close to the car in front of me, at least 2 car lengths as we were sitting in traffic and all trying to merge left, thankfully this time I was able to take control of the brake because I was going at a speed of ~5 but it scared my special needs son to the point of not being able to go back over that bridge.

NHTSA ID

11430610

Incident

Aug 25, 2021

On May 9th we were driving on the freeway at around 3 pm on a sunlit clear day. It was a straight section of road. Dry pavement and traffic moving reasonably well. The car in front of us was at least 100 yards in front of us and about the same for the vehicle behind I believe. We were going around 50 mph. The car slammed on the brakes so hard the seat belt restraints engaged as we flew forward, enough so that my wife and I were both sore the next day. Items on the back seat flew onto the floor. If there had been a car behind us we would have been rear ended and potentially a multi car pile up. We took the car to the dealership the next day. They had the car for the day and returned it saying everything is calibrated as it should be. I have called Acura and they set up a case number and a case manager and said they would call me. They have not called nor returned my repeated phone calls. I have asked for a supervisor to call and that has not happened either. Acura’s case number is 12213602 and Simon is the case manager. His phone is 800 999 1009 x87723. The supervisor’s name is Terry. I don’t have an extension number for her. We have grandkids that ride in car seats in the back seat. Thank god this didn’t happen with one or both in the back seat with a car behind us. We have been driving cars with the braking feature on them for 10 years now (Ford and Infinity) and have never had anything like this happen. We’ve had the adaptive cruise pick up on something in the past and ease off the accelerator but never anything like this. The cruise was not engaged when this occurred. In googling this it sounds like we aren’t the only ones having this issue.

NHTSA ID

11420161

Incident

May 9, 2021