subin

This happened on the 2019 TLX A-Spec loaner. I have 2019 RDX and someone from that forum also reported this same issue.

I was on the freeway with ACC and LKAS on cruising at about 65 mph.
When the car followed the freeway to a left hand curve, we met a traffic jam and the collision mitigation "brake" warning came on flashing and I stepped on the brake with about two car distance from the car in front of us.
Then, it felt like the brake hold was activated and all the warning lights came on with the system reporting ACC failed, brake failed, etc. going through dash. I stepped on the gas a bit more and the car started moving and I was still able to drive it.
I then got off freeway and found a place to park, stopped the engine, opened and closed the door, and restarted it. That did not help, but as soon as I put the car to "Drive", everything went back to normal.
I would believe that it was a glitch.

csmeance

My guess would be sudden braking may have caused the brake fluid sensor to sink/jostle during hard braking making the car freak out that it's loosing fluid or some other oddity.

JonfromCB

I've had similar problems with my 2019 Advance. In shop again for 5th time. Mileage 5K. Three times when backing up from parked position the emergency brake/transmission locks up. Each time I was in traffic.
After turning ignition on and off several times and several minutes of activating parking brake several times and switching transmission between D, R, and N operation returned to normal, This is a safety issue of the 1st magnitude. I'm afraid to use reverse anywhere other than backing from my garage. 2nd issue, much like OP, 5 times while driving the emergency brake, check engine, and emission systems warning lights all come on simultaneously. 3rd issue, collision warning lights come on spontaneously when driving. Called Acura Client Relations today to open a "case". Dealer says they will request factory rep' assistance. Was told repeatedly it was a software problem and not a sensor, brake system, emission system or computer problem....Personally I don't think they don't have any idea what the problem is as they keep updating the software and it keeps reoccurring.... What's the saying about when they keep doing the same thing over and over expecting different results?

JonfromCB

Update. Received call from dealer this PM. Acura told them to replace the catalytic converter. I want to be optimistic, but after 5 service visits and repeatedly being told it's a software issue, it's suddenly become a bad catalytic converter causing three different (emergency brake, collision mitigation, and emissions) problems? I'll post updates as they unfold. BTW, this is my third TLX Advance.

Rocketsfan

Like I've posted in other threads like this. There are several problems that seem to cause every warning in the car to seemingly go off. lol. Everything from battery issues to wheel issues to now this, I guess. What I usually tell people is to go to the dealer so they can check the codes. Just because it "goes away" doesn't mean it was a "blip". There may be something serious that wrong, and you more than likely can't diagnose it.

Your transmission locking up is really bad, though. That's scary. Please keep us updated.

Christopher.

I had this issue happen after I had to have the wiring harness replaced, they did something to resolve it but I don't recall exactly what. Then last December I had engine failure and the engine had to be replaced - with COVID related shortages, this took months (the whole time I was in their loaner car, so I actually have no complaints about the delay). A couple days after I got the car back, I had the "all the warning lights" and basically all the computer systems fail and reduced engine power. I took it in, they said they couldn't find any problem so it was related to my Sprint Booster - I OK'd them removing the Sprint Booster - well, now I got the car back and the same problem happened, so absolutely nothing to do w/the Sprint Booster (which I was highly skeptical of, but, had no proof to support my skepticism until today).

EDIT: they did tell me that it's typical to experience this sort of "cascade" of malfunctions when one part of the system fails though.

Christopher.

The latest occurrence for me was triggered by honking my horn