Greetings. I have a 2018 4Runner TRD Off Road Premium, and according to the manual, it's equipped with something called "Hill Start Assist Control". I thought that it's meant to prevent the car from rolling backwards when you're on an incline and take your foot off the brake. My vehicle has never done that. It starts rolling backwards the very second I take my foot off the brake pedal. I've gotten in the habit of using my left foot on the brake when I'm taking off on an incline. I had a 2000 Jeep Grand Cherokee and it had that feature, so I naively thought the 4Runner would behave the same.

So when I had the car in for a 15K service at the Toyota dealership, I asked the service rep about it. He thought I was confusing it with the Downhill Assist Control. When I got back home, I looked at the sticker that was originally on my vehicle, and it said clearly that it's equipped with the Hill Start Assist feature. So I called the dealership back and took the car in again. I was talking to two different service reps there and was getting different answers to whether or not my vehicle was equipped with it. One of the guys pointed to the CRAWL control knobs, and said that it was the same. I told him that CRAWL control was for 4 wheeling, and would only engage when the car is in 4 wheel drive low. Anyway, long story just a little longer, they took the car in and had two mechanics verify that the car is equipped with it, and that it was working properly. When I picked the car up, the service rep explained that it isn't exactly what I thought it was. He said that the feature essentially brakes automatically if the vehicle is rolling backwards.

While this is useful for preventing the vehicle from picking up speed, it's not very useful for helping you start on an incline. I can live without this feature, no problem, but I find it very odd that a company like Toyota would 1) advertise a feature that doesn't work as explained, and 2) barely document how it's supposed to work, 3) not train the service reps to know about this feature. The only documentation in the handbook is a blurb like "Helps to prevent the vehicle from rolling backward when starting on an incline or slippery slope". This sounds logical, but according to the service rep, this isn't really what it does.

So, I'm wondering if this feature just doesn't work on my vehicle, if the Toyota service rep doesn't know how it's supposed to work, or if this is the expected functionality. Would love to read about what other 5th Gen 4Runner owners have to say. Thanks.

the normal operation is that it let's you roll some then acts and sounds the same as traction control going off. it does not prevent you from rolling, just slows you from rolling a lot, so IMO it's not very useful. in situations where you don't want to roll back you'll need to left foot brake.

to test it find a spot where it's safe to roll backwards, i bet it stops you in maybe 5' (which doesn't make much sense to me)

Being in Florida there's little to no chance that I'd ever need this feature..Hwoever, I found out that I had it while visiting my property in West Virginia. We were stopped on a gravelly road going up a hill..I went to start going and heard this clicking/buzzing sound..scared the crap out of me..fortunately, my mom was with me who lives in Colorado and happens to own a 4R as well said it was normal..

Doesn't work too well.

Does go crazy when you roll back too much.

Mine rolls back a little, makes noise and gently brakes a time or two. Then it will roll back. Not good if someone is close behind you. I think of it as a warning, not a real help.

Playing with it one time, I let it continue to roll back after the noise quit and it kept rolling until the brakes or transmission stopped it hard and killed the engine. Won't do that again. As others said "scared the crap out of me".

RTFPost, he quotes the manual in the first sentence. You then admit you have no solution to his post, what a joke.

I think it works perfectly, it warns you that you’re rolling backwards and slows you down so you don’t jerk the throttle when you take off. Hill HOLD is simply not a benefit on anything but a manual or dual clutch transmission. If you happen to be on a very steep hill (since automatics don’t roll back on slight inclines) the hill start assist will give you plenty of time to move over to thegas pedal.

Having owned a vehicle (also a Jeep) that had a Hill Start Assist that works as the OP explained, I strongly disagree. If you have to have your left foot on the brake, it absolutely does not work perfectly.

I see little point of this feature in an automatic transmission equiped vehicle. Does not prevent you from rolling back but does give you an annoying noise to alert you if you do. When stopped on an incline waiting for the light to change you need to be attentive to your surroundings on all sides as well as having your foot firmly affixed to the brake pedal.
This feature would be alot more useful with a manual tranny but if it works the same as it does on my auto which slides back several feet all the while making a god awful sound while getting uncomfortably close to the guy behind me then I'm fine not using it and calling it out as a dumb feature altogether. I wonder how much this and all the other BS nanny features cost me out the door.

What possible on road situation would you need to use both pedals? It’s just not an issue, i have a steep driveway and it only rolls back less then half the time. Unless you have a manual or dual clutch transmission, which will roll back in a slight breeze, you just don’t need a system that holds the brakes. With an auto you can just use the throttle to hold your position if needed. BTW I have a car with a DSG transissions that likes to roll back and does NOT have hill hold and I’ve never had to double pedal it, never.
I feel like the 4Runner system is really to keep you from coming off an obstacle too fast or jerking the throttle trying to get up an obstacle.

towing

Okay, that’s a whole different ball game. This system isn’t designed to hold trailers or even the vehicle in place. It’s basically meant to prevent a loss of traction from jerking the throttle when rolling backwards. On the newer Toyota systems you can jam the brake down for a few seconds and the car will HOLD the brakes when released.

YouTube

The point is that it doesnt work the way other manufacturer systems work, it doesnt work the way its described even in Toyota videos, it doesnt work the way someone would expect even if they had read the owners manual

I was disappointed with my 2017 4Runner Limited's hill assist. As others mentioned, it only slows the roll, not prevent it.

I have this same feature with our 2011 Rav4 V6 Base and 2011 Prius III. Their hill assist actually holds the brake for 2 seconds before letting go or until gas pedal is engaged. To engage it on these vehicles, I had to press on the brake pedal further than normal for 1 second and a traction control icon will blink to show that this feature was engaged.

This feature activates for me frequently in winter, sitting on the poorly heated and long ramp which goes up into the garage at work. (There is a card reader at the top to get in so must stop) I've let the vehicle slide all the way back down again just to see what happens. Anti lock goes nuts trying to maintain traction - it obtains it mind you but the vehicle still rolls down under its weight but nice, slow and controllable. I suppose that is the point of it.

The answer you got that it is similar to crawl control is correct in one way as the system uses the anti lock and wheel sensors to judge speed of the vehicle moving backward and ensure it stays straight and controllable in order for you to apply throttle again which will turn it off. I suppose the intention here is to allow the driver to regain control of a vehicle or at least steer it properly were it to be sliding backward while in drive, again - similar to trying to fish tail the truck in snow which is quickly killed in the same manner by the stability control feature.

So you are right, Toyota advertises the feature incorrectly and probably should not refer to it like that, has poor documentation on it - yup, and service reps well - depends on where you go of course. I'm not surprised this is poorly documented so is a fabulous feature like crawl control itself or how to use the manual transfer case properly but I guess they can't cover all the bases who knows. These quirks is why you love it I'm sure!