Acura owners love their vehicles. The automaker has established itself as the most affordable luxury brand and several Acura models are consistent award winners. Two SUVs, in particular, have earned numerous accolades in the past few years: the Acura MDX and the Acura RDX. The MDX also has a substantially longer ownership term than most luxury cars.

However, a group of MDX and RDX owners and lessees have filed a class-action lawsuit against Acura — technically American Honda Motor Company, Inc. — for a dangerous deceleration problem. 

A closer look at the Acura MDX & RDX class-action lawsuit

The lawsuit alleges that 2016-2020 Acura MDX and 2019-2020 Acura RDX models experience rapid, sudden deceleration, significant hesitation during acceleration, and the transmission unintentionally shifting into neutral while driving, causing the engine to stall.

Alarmingly similar to Toyota’s tremendous 2010 recall due to unintended acceleration problems, the Acura issue seems to be caused by a defect in the software that controls the throttle-by-wire system.

According to CarBuzz.com, “There’s a miscommunication between the vehicles’ computers and software, which controls the engine, throttle, and transmission. The throttle-by-wires systems, in other words, are not functioning properly.”

An exceptionally dangerous issue

The reported Acura MDX and RDX issues are, of course, extremely dangerous. ClassAction.org states in plain language, “A class-action lawsuit has been filed alleging a defect is causing the vehicles to decelerate when the driver steps on the gas pedal. The vehicles may then stall and shut down, only to return to normal functioning as if nothing happened.”

Think about how incredibly scary that must be. In a luxury vehicle that’s no more than four years old, every time you step on the gas pedal you have to live in fear that the SUV may not accelerate at all, or worse, it may stall out altogether.

Miraculously, so far no accidents have been reported by MDX or RDX owners, but CarComplaints.com does report a specific instance where a driver got stuck in traffic because of the issues alleged in the class-action lawsuit. The driver said, “I got into [a] traffic jam and suddenly the vehicle could not move and the gear shifted to neutral. I tried to re-engage the gear several times to no avail.”

Is Acura “pulling a Toyota?”

Even worse than the Acura MDX and RDX deceleration problems themselves is the fact that Acura reportedly has known about the issues since 2016, but has refused to address them. CarComplaints.com documents a substantial number of complaints that mention “hesitates on acceleration” dating back specifically to 2016 Acura MDX models. 

In another case documented on CarComplaints.com, one of the class-action lawsuit plaintiffs, a 2019 MDX lessee in Florida, experienced problems with his vehicle from the beginning. He brought the vehicle into the dealership for repairs, where they ultimately kept it for four weeks, replacing the rear differential and brake booster. Although parts were replaced, the plaintiff’s MDX was returned to him in even worse condition than it was previously. 

Another plaintiff, this one an RDX owner in California, reports a similar issue — except in his case, Acura refused to even acknowledge there was a problem with the vehicle at all. Again, this is shaping up to be eerily similar to the way the Toyota acceleration recall litigation played out.

If you’ll recall, Toyota was found to have knowingly concealed the issues and didn’t follow standard recall protocols, resulting in the company having to pay over $1 billion in fines. 

The Acura class-action lawsuit was filed in early May 2020, so the case hasn’t gained much traction yet, but the automaker is expected to formally respond to it soon.