While driving on a freeway for about 15 minutes at 65 MPH, the MIL indicator started blinking. The vehicle began to rapidly shake, while the engine power decreased significantly. The engine dramatically went from 65 mph to 35 mph causing a safety hazard while driving on the freeway as we attempted to exit and pull over safely. The vehicle is a 2021 Acura RDX and is driven approximately 10,000 miles per year. All maintenance has been performed in accordance with the manufacturer's schedule. It has not been involved in any collisions or other user risk other than normal driving in accordance with the approved use of the vehicles. Upon trying to restart the vehicle, the vehicle continues to violently shake while in park. Notification lights indicating Brake Failure, AWD failure, Check Emissions System, etc. There were no other indicators that there was an issue with the vehicle prior to this instance on 4/20/2024. In fact, the vehicle was viewed by Cerritos Acura for its regularly schedule service on 4/10/2024 and no issues were identified by the dealer. As far as safety, we were traveling with two young children and the location of the freeway did not have a safe place to pull over. The sudden reduction in speed also put us in risk with surrounding vehicles. This appears to be related to TSB 20-053, however, no communication have been identified or communicated by the dealers to the the owner/operator of the vehicle.

- Lakewood, CA, USA

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.

- Collierville, TN, USA

While sitting in a long row of stopped vehicles at a traffic light for an extended amount of time due to an accident I had the Automatic Brake Hold feature activated { I did not have to have my foot on the brake while sitting still) as well as the Auto Idle Stop OFF button meaning {the engine shuts down when you come to a stop.} Apparently, the Brake Hold feature timed out with no warning whatsoever and because the vehicle moved forward the Auto Start Stop feature activated at the same time and the vehicle lurched forward rear ending a new expensive SUV in front of me. The impact was hard due to the quick lurch of my vehicle. I have damage to the front of my vehicle and all of the electronic features started flashing including the emission control. The driver advised she was very shaken up and if a pedestrian or bicyclist had been in front of us it could have been very tragic.The vehicle is being towed to A local Acura dealer for evaluation and I have a Case number assigned by Honda with no case manager assigned yet. There were no warning lights/lamps at all prior to the vehicle Brake Hold timing out and further searching through the manual only says it times out after 10 minutes but does not advise what happens when that happens or what warning will be used.

- Ft Myers, FL, USA

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.

- Media, PA, USA

I have a 2021 RDX. Was on the interstate moving at about 70 MPH coming back from Missouri. Raining. Lots of semis creating huge following misty, hard to see rain. Decided to accelerate to pass a couple. Car nearly stalled and acted like it had lost a cylinder's worth of power. Turned on hazards, slowed, pulled over and lifted the hood hearing all kinds of unusual noises. Shut the car off and restarted. All was well. Turned all lane-keeping, etc. off including cruise. Drove the last 100 miles or so without incident. Called dealer and was told likely didn't pull a code. Don't worry and keep driving. Said to make sure front of car was clean. Duh!! I keep my ride spotless (unless driving in the rain). Called CA's Acura line. Absolutely no help. 2 different females had no idea what limp mode was. Read quite a bit since then finding out it could be the result of many things including problems that could damage the motor and/or tranny. WOW!!! Had never heard of "limp mode" before. Nice that no info on this possible problem was anywhere in any user manual. Car has performed flawlessly ever since. So far, I guess the rain had interfered with the "radar" system and confused the computer. I'm thinking about buying a 40 year old car that doesn't have any of the modern computers etc. Later found info regarding TSB 20-053 which explains the problem and proposed solution. 06-26-2022 06:52

- Indianapolis, IN, USA

I was accelerating up a hill on a WV highway in a steady rain, the engine cut power, the check engine light flashed on and off, further throttle input did nothing, the car slowed on its own. I had to pull over from the left lane dangerously cutting in front of vehicles in the right lane as I could no longer maintain highway speed. Shut the car down and waited to rekey. Vehicle has operated fine ever since. The dealer has not been able to duplicated the issue (two weeks afterwards)

- Arlington, VA, USA

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.

- Sweet Valley , PA, USA

during acceleration on highway to pass a vehicle the Acura RDX lost power and decelerated. Check engine light came on....engine lost power to accelerate/maintain highway speed almost causing an accident.

- Holtsville, NY, USA

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.

- Fairmount, IN, USA

Driving at night in rain on interstate 81N in southern Virginia. I pressed accelerator all the way to pass and the car downshifted and then lost power. The engine light was flashing. I did not have enough power to maintain adequate highway speed while in the midst of a passing maneuver. While car was decelerating (with foot on accel pedal with no apparent response) I activated hazard lights and made my way across traffic to the shoulder. 70mph speed limit. I dropped to 50mph or so rather quickly amid traffic that put me and the traffic around me in a dangerous situation. Once stopped on shoulder (again in a dangerous situation that I'd prefer to avoid), i turned ignition off for 10 seconds and then restarted car. Situation seems to have cleared up; no engine light flashing and full? power. It did not happen again when I pressed accelerator to floor to recreate situation. This vehicle has 3800 miles on it.

- Kinnelon, NJ, USA

Incident happened on, 22 July 2021- Rainy day, accelerated vehicle to pass, vehicle went limb unresponsive, check engine blinking, needed to stop in Highway 4. Almost got rear-ended by semi trailer, fortunately made maneuver for emergency stop. Turned vehicle off for a few minutes, while my heart settled and turned vehicle back on check engine was no longer blinking and vehicle was once more responsive. 24 July 2021, I am currently in Acura Autonation Dealer in Sanford for maintenance appointment and informed them of issue. I am waiting for their system to come up since they are currently having issues, hopefully I will receive further info on malfunction of vehicle.

- Titusville , FL, USA

Brand new 2021 RDX - bought 3 days ago, only 128 miles. Driving on highway and it suddenly loses power. Was able to get to shoulder, but unable to get enough power to exit the highway to find a safer place to park. Check engine light and several transmission warnings indicating I should see dealer immediately. As vehicle came close to a stop, it shuddered and clunked so badly it seemed like I ran something over, but nothing was there. Tried to shut vehicle down and restart, but constant error messages and would only lurch a little. Had to have vehicle towed to dealership, but of course they said they never heard of this happening before.

- Cypress, TX, USA

I was driving in the rain, accelerated to pass a vehicle and the engine lost power. The check engine light came on and the car went into "limp" mode. The car would barely go 40 mph on a highway and the speed seemed to be continuing to decrease. Luckily I was able to pull over and shut the car off. Restarted, the problem appeared to go away. This is a very dangerous situation and I have read other people reporting similar incidents.

- Gaithersburg, MD, USA

2021 RDX A-spec 7322 miles northbound Hwy 95 Nevada to Oregon, raining. Attempted to pass semi, car behind me also passing semi, sudden loss of power, almost hit from behind, risk of on-coming traffic, able to move to right behind semi. Feeble response to any attempt to accelerate, barely limping along, moved to right shoulder and then to pullout, blinking check engine light, no other warning indicators. Idled engine for several minutes, continued to run rough, would not rev, check engine light cycled off, then back on (blinking), then off over period of several minutes. Turned engine off, waited 10 min or so, restarted ok, finished rest of 600 mile journey scared to pass lawnmower. Life-threatening event for my wife and I, several moments of sheer panic. First time this has happened.

- Gearhart, OR, USA