This is the first car I've driven with any lane safety feature so I've had no experience with the stronger Lane Keep Assist (LKA). I have driven the car for about 1000 miles now and to be honest haven't really noticed the Lane Departure Assist (LDA) at all. In fact I turned it off for about a week because sometimes I have to cross a line and the beeps are annoying. After turning it on I noticed once that the wheel moved a little by itself when I idled onto the line. I was paying attention though so wasn't really that useful in that case. HOWEVER, tonight it proved its not completely useless. I was on my way home and the on-board navigation rerouted me due to traffic. The Toyota Nav system isn't always the clearest and because the 11.5 inch screen is so long I had to look down a lot more. I took an extra second looking at the screen and didn't notice I was drifting slightly. Before my car even got to the right edge and beeped I felt the wheel pulling me back to center and I immediately looked up and the car was already correcting to the center again. I know there were some complaints/disappointments that this is LKA and I wish it was too. But I sure was glad the LDA was working as intended tonight.
To keep it from beeping when you change lanes, touch the turn signal in that direction. It will cancel the LKA.
I've also had positive experiences with it. I generally only use it when on lengthily Interstate trips and not on surface streets.
It's great if you are exhausted and worried about those open-eyed, dead brain, long 5 am drives to work in the morning. I keep all my stuff at the highest sensitivity. Lets just say my car offers me lots of coffee. lol
I know, being trollish, but: that portrait oriented laptop embedded in the dash is the villain in this tale?
Another possible villain is Toyota's insistence that almost any little piece of information triggers a very distracting popup on the MID, covering whatever screen you are using for operating the vehicle. It was very distracting at night when I foist drove the car home. I believe Toyota should be cited for this distraction and be required to modify its software to minimize the popups. They are too dangerous!
How about the pop ups telling you the radar is now ready or whether or not it sees a car in front? Apparently this information is important enough to interrupt your driving concentration.
I had to shut mine off. After using the car for about 6 months with it on, I was driving and it went off. My wife asked me what it was and I told her. Now I was getting 2 alarms for every crossing, one from the car, one from my wife. It seams that I'm only able to shut one of them off.
At least it goes back to your previous screen automatically. In the Gen 3, it doesn't. So you have to press DISP to go back to your previous screen.
After driving our 2017 Prime for about a year and a half, I have never noticed any "Lane Keep Assist" operating although I frequently hear the beeps from the Lane Departure Alert. According to the owner's manual: I have set these functions to "On" and to "High" as indicated. It is not reassuring that the manual notes that, for various random reasons, the LDA may not operate. The information about ABS, VSC, TRAC and PCS is not immediately helpful because the definitions of these abbreviations are quite difficult t find elsewhere in the manual: So, that's all I know about the LDA system. I could not find any mention of "LKA" or "Lane Keep Assist," although it is implied in the description of the LDA system as "LDA steering assist mode." My question is: how can I figure out if "steering assist mode" is actually working? Obviously, I could take the Prime out on a lightly-traveled straight section of highway, drive at a constant speed of about 45 mph, and let he car "drift" of its own accord just to see if the steering assist kicks in. But, given the disclaimer "the driver may not feel that the function is operating or the function may not operate at all," it's difficult to interpret the results and/or non-results. In many ways this is reminiscent of a Eugène Ionesco "theatre of the absurd" play where, after answering the doorbell several times with random results, one of the characters concludes: "When the doorbell rings, sometimes there is someone, other times there is no one."
Check for intermittent shorts or grounds in the doorbell circuit. More seriously, I don’t know of a reliable functional test for the LDA system. The relevant Operation Check topic in the Repair Manual (more info) just has you use the switch on the steering wheel to turn the system on and off, which tests not only the switch and indicator, but also presumably invokes a built-in self test. I imagine Toyota intended that the system’s self-monitoring and self-diagnostic capabilities would be sufficient: if there are no warning lights or messages such as “Lane Departure Alert Malfunction Visit Your Dealer” or “Lane Departure Alert Unavailable,” then the LDA system, including its steering assist function, should be able to operate under the expected conditions, many of which are described in New Car Features.
