2021 Acura RDX Problems

What owners report

Owners of the 2021 RDX report two distinct kinds of trouble. Very early in ownership, some describe sudden loss of engine power with a flashing check engine light, usually while accelerating or merging in rain. Over the years, a large share of complaints concern the panoramic sunroof and rear tailgate glass — either popping or cracking sounds from the roof over uneven ground, or glass that shatters without any impact.

1. 1
   Body and structure

   Panoramic sunroof popping, cracking or shattering

   • 19 complaints (16%)
   • median 30,000 mi at 4.5 yrs old (3 state mileage, few)
   • 2 mention a crash, fire or injury
   • filed 2021–2026

   Owners describe a loud knock or pop from the roof when the car twists over a curb, ramp or driveway at an angle. Others report the panoramic glass breaking outward on its own at highway speed with a loud bang, leaving glass on the roof and inside the cabin. Some say the dealer acknowledged the noise but had no lasting repair, and a few note a service bulletin exists while glass replacement parts were backordered. Reported from a few thousand miles up to around 56,000 miles, often in cool weather and on uneven pavement or ramps.

   3 related service bulletins

   What to check: Drive the car over a curb or driveway at an angle with the radio off and listen for popping from the roof. Look for previous sunroof glass or frame replacement and ask whether the service bulletin for the sunroof motor control unit was applied.

   2 excerpts from owner complaints in NHTSA records

   “My sunroof exploded for no reason while traveling at highway speeds. Fortunately my sunshade was closed preventing shattered glass from entering the cabin which could have injured me. Shattered glass also damaged the paint on top of my vehicle which will require repainting. The noise made by the glass exploding startled me and could have caused an accident in addition to the glass that flew off of the vehicle endangering vehicles behind me.”

   NHTSA complaint #11594354, filed 2024-06

   “Brand new 2021 Acura RDX panoramic sunroof exploded less than 2 weeks after purchase. I was driving when all the sudden, out of nowhere, there was a loud pop/explosion sound. I immediately pulled over and inspected the but didn't find anything. Not one scratch or dent anywhere. It wasn't until I was getting back in the car, and heard the sound of glass slowly shattering, that I realized it was the sunroof. Nothing external hit the car to cause the explosion/shatter. …”

   NHTSA complaint #11420647, filed 2021-06
2. 2
   Visibility (wipers, defrost, mirrors)

   Rear tailgate glass shatters without impact

   • 52 complaints (44%)
   • median 15,000 mi at 1.4 yrs old (9 state mileage, few)
   • 1 mention a crash, fire or injury
   • filed 2020–2026

   Owners report the rear window breaking or shattering while the car is parked in a driveway or garage, sometimes shortly after starting it or closing a door. The glass is described as blowing out with no object nearby, leaving shards in the tailgate and on the cargo area. Some say the dealer declined warranty coverage or pointed them to a glass shop, and one owner reports the model year not being covered by a rear glass bulletin. Reported from a few thousand miles up to roughly 75,000 miles, often in cold weather and while the vehicle is stationary.

   What to check: Inspect the rear glass and tailgate for replacement traces or glass residue in the tailgate cavity, and ask whether any previous rear glass breakage was covered under warranty.

   2 excerpts from owner complaints in NHTSA records

   “On 10/2/2022 the rear glass shattered on my RDX for no reason. It was parked in the driveway. Safelight replaced the glass but was unable to get the glass out of the tailgate and shards were being randomly released. I then had the entire tailgate/glass replaced with original Acura tailgate/glass. On 5/7 /2023 the glass shattered again for no reason. Parked in the garage with door closed. I attached pics of both incidents. The last two pictures are from the 10/2 incident.”

   NHTSA complaint #11520817, filed 2023-05

   “Got in my vehicle as usual, started the vehicle shortly after I heard cracking thought nothing of it and all of a sudden the rear tailgate window shattered completely.”

   NHTSA complaint #11720321, filed 2026-02
3. 3
   Air bags

   Front passenger seat sensor and airbag recall parts delay

   • 10 complaints (9%)
   • typically at 3.4 yrs old
   • filed 2024–2025

   Owners report that the front passenger airbag shows as off for a small or light passenger because the seat weight sensor does not register them. Others describe long waits for the occupant classification sensor recall remedy, with dealers confirming parts were not yet available, and some note the airbag warning light behavior. Reported across a wide mileage range, largely tied to the recall notice period rather than a specific mileage.

   Recall 24V064000Recall 26V332000

   What to check: Check whether the occupant classification sensor recalls were completed on the VIN, and have a light adult sit in the passenger seat to confirm the airbag reads on.

   2 excerpts from owner complaints in NHTSA records

   “I have been trying to get my vehicle repaired for over a year in response to recall number 24V-064 with no success. The vehicle manufacturer is not providing the required parts to the dealership to address this recall from early 2024. I think additional action needs to be taken against the manufacturer to drive improved behaviour to address safety recall issues in a timely manner”

   NHTSA complaint #11643177, filed 2025-02

   “Remedy is available for the recall, but Honda will not fix the recall on my 2 vehicle’s that I own with this open recall. They are saying 2025 maybe. Unacceptable.”

   NHTSA complaint #11595398, filed 2024-06
4. 4
   Engine

   Sudden loss of power with flashing check engine light

   • 16 complaints (14%)
   • typically at 2.0 yrs old
   • filed 2021–2026

   Owners describe the engine dropping into limp mode with a flashing check engine light, usually while accelerating to pass or merge, often in rain. Throttle input does little, speed falls on its own, and restarting the car after a few minutes usually restores normal operation. Several say the dealer could not reproduce the problem, while others report software updates or a diagnostic code stored. Mostly reported between roughly 100 and 12,000 miles, often during wet weather and at highway speeds.

   3 related service bulletins

   What to check: Ask for the service history for any check engine work, PCM or PGM-FI software updates, and whether codes such as P0087 or misfire codes were stored. A scan for stored or pending codes before purchase is worthwhile.

   2 excerpts from owner complaints in NHTSA records

   “It was raining and I was sat at a stop light. The brakes started to slip a little no matter how much I pressed then all of a sudden the entire car started shutting down. Engine, Transmission, Power Steering, Lane Keep Assist, Collision warning, all the lights started flashing. The car was put into Limp mode.”

   NHTSA complaint #11659951, filed 2025-05

   “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)”

   NHTSA complaint #11484165, filed 2022-09
5. 5
   Brakes

   Brake squeal at low speed in cold weather

   • 5 complaints (4%)
   • median 700 mi at 0.2 yrs old (2 state mileage, few)
   • filed 2020–2023

   Owners report a high-pitched squeal when the brakes are lightly applied at low speed, and some describe louder noise and extra pedal effort in reverse. Some say the dealer told them no fix was available at the time, while others report the noise easing once the brakes warm up. Repeated service bulletins describe the same cold-weather squeal condition. Usually reported at low speeds below about 15 mph in cool conditions, sometimes on nearly new vehicles.

   5 related service bulletins

   What to check: Test the brakes at low speed on a cold start, in both drive and reverse, and listen for squeal. Ask whether the brake shim or damping bulletin work was performed.

   2 excerpts from owner complaints in NHTSA records

   “There is a horrible clunking noise coming from front when driving or turning (possible passenger side). It doesn't matter what your speed is. It sounds like it may be the suspension or struts and it's so bad that it sounds like my front end is falling apart. With only 2400 miles it has gotten worse and worse. Dropped it off at the dealers this morning and service tech drove it around building to come back and say how bad it sounded. He says he hasn't ever heard this noise. …”

   NHTSA complaint #11383297, filed 2020-12, 1,200 miles

   “Rear brakes: Rear brakes and rotors make odd noise or extraordinarily high pitched screeching sounds coming from outside the car when your brakes are applied. When using brakes in reverse the noise is very load. This happens when all the time wither the vehicle is cold or warm. Driver must use additional force to stop vehicle while in reverse. I have made numerous complaints to the dealership, they are aware of the ingoing problem with the 2021, but they currently do not have fix for the problem. …”

   NHTSA complaint #11510123, filed 2023-03

Buying note. Check for completed recalls on the VIN, especially the front passenger seat sensor campaigns, and budget for potential glass work on the roof and tailgate. A cold-start test drive over uneven pavement and a low-speed brake check will surface the most commonly reported symptoms.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.