2021 Acura TLX Problems

What owners report

Owners of the 2021 TLX most often describe drivetrain trouble, particularly on SH-AWD versions where the transfer case splines strip and the car quietly reverts to front-wheel drive, along with transmission failures, leaks and hard shifting. Brake noises and shudder, spotty infotainment screens and speaker crackling, and driver-assist warnings that cut in during rain or snow come up next. Many of these reports arrive between roughly 25,000 and 90,000 miles, while a cluster of brake, radio and start-up complaints were filed on nearly new cars.

1. 1
   Transmission and drivetrain

   Transfer case splines strip and AWD stops working

   • 23 complaints (32%)
   • typically at 5.5 yrs old
   • filed 2022–2026

   Owners of SH-AWD and Type S cars describe a pop, clunk or shudder from underneath, after which the rear wheels stop getting power and the car behaves like a front-wheel-drive vehicle. In several reports no warning light or message appeared at the time, and owners say instability or oversteer was noticeable afterwards. Dealers who inspected the cars described stripped splines between the transmission and transfer case and, in many cases, replaced one or both units, some under warranty and some quoted to the owner. Mostly reported between about 16,000 and 86,000 miles, often during ordinary driving with no advance warning.

   What to check: Ask for service records showing whether the transfer case fluid was ever checked or changed, and have a shop put the car on a lift to confirm the rear wheels turn under power. A test drive should include a hard acceleration to feel for shudder or loss of drive.

   2 excerpts from owner complaints in NHTSA records

   “The all wheel drive failed do to transfer case splines being sheered off between the transmission and transfer case. No warning lights are on to warn of the rear wheel tires not receiving power to them. I was not aware of this problem and this could have contributed to and accident, as I though the AWD was working, but it wasn't.”

   NHTSA complaint #11725554, filed 2026-03

   “My vehicle was performing as expected, but there was a smell of burning oil or rubber. When I took the car into the dealership the found that the transmission was slipping and the transfer box was failing. In the video they sent of the initial inspection there is obvious brown sludge leaking from the transmission. I was told that a complete transmission and transfer case was required.”

   NHTSA complaint #11724400, filed 2026-03
2. 2
   Transmission and drivetrain

   Transmission leaks, slipping and failure to upshift

   Mentioned in 8 of 60 sampled complaints

   Complaints describe fluid leaking from the seal between the transmission and differential, brown sludge visible during inspection, slipping, and in some cases the car refusing to shift out of first gear or banging into reverse. Owners report that dealers replaced the transmission, sometimes together with the transfer case, and some were told warranty coverage was uncertain because of mileage. In one report the transmission failed again shortly after a fluid service. Reported from roughly 70,000 to 93,000 miles, usually after normal driving rather than a specific event.

   1 related service bulletin

   What to check: Check under the car and on the garage floor for reddish or brown fluid near the transmission, and ask for the transmission fluid service history. Note any delayed or harsh shifting during a test drive.

   2 excerpts from owner complaints in NHTSA records

   “I took this vehicle to get serviced in the summer of 2025. I recently joined an Acura Type S (2021+) group on Facebook and learned that the issue is quite prevalent. I had to have the transmission and transfer case replaced due to transmission issues and traction issues”

   NHTSA complaint #11750163, filed 2026-07

   “I am reporting a transmission failure in my 2021 Acura TLX with approximately 84,300miles. While driving under normal conditions, after about 30 minutes on the road, I came to a stop at a red light. When I attempted to accelerate again, the vehicle would not shift out of first gear. The engine would rev, but the transmission failed to upshift. I also experienced a hard and abrupt engagement when shifting the vehicle into reverse. …”

   NHTSA complaint #11733596, filed 2026-04
3. 3
   Forward collision avoidance

   Driver-assist warnings and unexpected braking

   Mentioned in 8 of 60 sampled complaints

   Owners describe a message that some driver assist systems cannot operate because the radar is obstructed, with the indicator turning from green to orange, most often in rain or snow. In several reports the car then slowed sharply on its own without the brake being pressed, at speeds from about 35 to 85 mph, and returned to normal after a while. Others report the collision mitigation system braking hard with no vehicle ahead. Reported at highway speeds in wet or snowy weather, with no consistent mileage pattern.

   What to check: Ask whether the radar and camera systems have had any software updates, and check that the windshield and front sensor area are clean and undamaged. A test drive in rain would show how often the system drops out.

   2 excerpts from owner complaints in NHTSA records

   “Driving towards the gas station, still at lows speeds while I was in the neighborhood so speed limit was 15mph. I can hear and feel the car struggle to move forward, about 2 minutes into the drive a hear a big TOON and check engine light is on for about a minute before going away. I filled gas and headed back home and I heard a larger TOON but this time all the warning light came up. …”

   NHTSA complaint #11723440, filed 2026-03

   “My wife and I were on the first day of vacation, driving from Virginia to FL by way of SC. Around 1pm I was driving the car on interstate 20 West in South Carolina near Bishopville. There were no cars in my lane in front of me and the car suddenly activated what Acura refers to as the CMBS system. The purpose of this is to stop us if it thinks we are going to run into another vehicle. I'm not 100% sure but I think this is related to the adaptive cruise control. …”

   NHTSA complaint #11500621, filed 2023-01
4. 4
   Brakes

   Front brake noise and pedal shudder

   • 7 complaints (10%)
   • median 270 mi at 0.7 yrs old (3 state mileage, few)
   • filed 2021–2026

   Owners report a spring-like click or cranking noise when pressing the brake pedal at low speed, a squeal or groan when the brakes are cold or after the car sits, and, in some cases, steering wheel shake and poor stopping response at highway speed. Dealers acknowledged the noise in some cases but told owners parts were not yet available, and in others replaced front rotors. Reported from nearly new (some under 20 miles) up to about 32,000 miles, often on the first brake applications of a drive.

   Recall 25V3910003 related service bulletins

   What to check: Listen for clicks, squeals or groans on the first few stops from cold, and feel for steering wheel shake when braking from highway speed. Ask whether any brake noise service bulletins were applied and confirm the brake pedal recall was completed.

   2 excerpts from owner complaints in NHTSA records

   “The contact leased a 2021 Acura TLX. The contact stated that while driving the vehicle, a loud abnormal, squealing noise would emit from the brake pedal upon depression without warning. The contact had taken the vehicle back to the dealer where they acknowledged the failure but stated that the parts for the repair were not yet available. The contact was given a loaner vehicle of the same model; however, the same failure occurred with the loaner vehicle. …”

   NHTSA complaint #11455498, filed 2022-03, 11 miles

   “The contact owns a 2021 Acura TLX. The contact stated while driving 55 MPH and depressing the brake pedal, the steering wheel started to shake, and the vehicle failed to respond as needed. A dealer was contacted, and the contact was able to schedule an appointment to have the vehicle repaired. No warning light was illuminated. The vehicle was taken to the dealer where it was diagnosed that the front brake rotors were damaged and needed to be replaced. The vehicle was being repaired. The manufacturer was not notified of the failure. …”

   NHTSA complaint #11648315, filed 2025-03, 32,000 miles
5. 5
   Electrical system

   Infotainment screen blackouts and speaker crackling

   Mentioned in 5 of 60 sampled complaints

   Complaints describe the display going blank, freezing or restarting, popping and crackling from the speakers, and loss of audio, sometimes after hitting a bump. Owners also mention the backup camera image failing to appear or appearing late. Dealers diagnosed loose or poorly made coaxial cable terminals in the media bus network and replaced the connector set in some cases. Spread across the model year with no clear mileage pattern; several reports came within the first few years of ownership.

   5 related service bulletins

   What to check: During a test drive, check the screen through a few restarts and listen for speaker popping. Ask whether the coaxial cable terminal bulletin was performed and whether over-the-air updates have been installed.

   2 excerpts from owner complaints in NHTSA records

   “Hi there, My car has been to the Acura dealer multiple times for the same issue, and I'm hearing that alot of other Acura TLX owners are having the same issue. My car screen will randomly short, and can just shut off. Sometimes when I'm backing up, the screen will freeze and i wont realize that someone is walking behind the car, almost causing me to hit them. The audio system also can make weird crackling noises as well. There are definitely some safety features that shut off with the screen, though i cant pinpoint them exactly.”

   NHTSA complaint #11530116, filed 2023-07

   “On October 4, 2026, at approximately 6:55 PM, the 2021 Acura TLX suffered a catastrophic and sequential collapse of its primary safety and electronic control systems while in motion. Without warning, the vehicle's dashboard suddenly illuminated with a cascade of severe system malfunctions, beginning with a critical Brake System Problem warning, immediately followed by a Power Steering System Problem, which caused the steering wheel to become dangerously heavy and difficult to maneuver. …”

   NHTSA complaint #11772571, filed 2026-10

Buying note. A pre-purchase inspection on a lift, focused on the transfer case, transmission seals and brake noise, is worth the cost on this model year, and confirm which open recalls have already been completed. Service records showing regular transmission fluid changes and any applied service bulletins are a reasonable thing to ask for.

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.