I know that Hill-Start Assist Control is standard on 2018s but I'm not sure how it works.

Our 2016 RX has automatic brakes and while you are stopped on an incline, when you let go the brake, the car will not roll back.

I tried GX on a small incline, and when I let go off the brake, GX starts to slowly roll back. I think on some of the older Lexus cars, to engage Hill-Start Assist you press hard on the brakes for a few seconds and you get a notification and a beep. I tried on GX but that didn't work.

How do you engage the Hill-Start Assist?

Thanks in advance.

 

I don't believe "Hill Start Assist" is standard on GX! Only DAC (Down Hill Assist) is standard on GX. With that being said, if your GX has the "Driver Support Package" option, the standard "DAC" will be replaced with "Crawl Control", for which you can use for "Hill Start Assist". The procedures will be: put vehicle in "4-Lo" mode, press "Crawl Control" to ON, release the break, the vehicle will start to moving forward at set speed controlled by "Crawl Control Speed Select". It works the same way if in down hill situation. Crawl Control can also be used in various off road situations as well. Think it as a special low speed off-road cruise control. Hope that helps for answering your question.

 

I guess something I've never really noticed using. Not sure how long it holds either.

Out of the '19 brochure...but I looked back in 2010 brochure and feature shows up there as well. Some references in the owner's manual as well.

 

FSM says---> Hill-start Assist Control: When the vehicle starts off on a steep hill, hill-start assist control detects the backward descent of the vehicle and performs 4-wheel hydraulic pressure control to reduce the speed of the vehicle.

• 
  Depressing the brake pedal cancels control of the hill-start assist control system.
  
• 
  The system does not operate when the shift lever is in P or N, or when the vehicle is being driven/rolling back up a slope with the shift lever in R.
  

 

Looking through my 2014 GX manual, there is nothing referenced with Hill-start Assist Control (HAC) at all. At the end of "Index" section, only has on line of definite of HAC, but with a reference of (if equipped) notion, but no reference of operation. I am wondering if this was an option for specific market configuration. What is the note "8" in brochure indicated?

 

In this electronic version of '14 owner's manual searching "hill-start" gets 16 hits... although I do see the "if equipped". I guess I need to try it out next time I am out in mine to see if it is there. It may be a specific market feature like you said.

https://lexusgxor.com/_media/general...ers_manual.pdf

 

I have an '18 premium and I can tell you from an experience that it has the HAC.

 

Is there a button to enable it or it just sort of be there automatically, say you are in "D" position on a hill, you release the break and vehicle just stays there until you hit the accelerator? If it is, that will certainly be another "undocumented" feature.

 

It should always be on but wonder if disabled when Traction Control is turned off

 

I can check it out after I get off work, but i noticed the HAC working while on a steep incline during a stop. And my 2018 brochure does say that it comes with it and doesn't specify if it is a option or not. .

 

There is no button, I just works. If you're on a steep hill with the nose of the GX pointed up and you start to roll back it'll kick in. It's similar to DAC when going down a hill, but much slower. It greatly reduces the speed at which it rolls backwards, but doesn't stop it completely.

I used to own a Mercedes G550, that car has a similar feature, but it didn't move at all. You could let go of the brake pedal, and the car wouldn't budge until you hit the gas.

 

I have a 2017 Premium. It's is always on. If I back out of my driveway and want to go up the incline of the street and the vehicle begins to roll backwards it kicks in with a shuddering of the brakes to let you know you are going in the wrong direction. It doesn't stop you completely but makes you aware something is amiss.

 

 

Agreed. This feature is more of a hill start "warning". Like "Put you damned foot on the brake pedal already!"

 

Mine works but not consistently. I park in a multi-level garage and always sit on an incline while waiting for the door to close behind me. Sometimes I can release the brake and nothing happens and other times the car will roll backward and start beeping at me. In either case I'm sitting in the same spot/at the same angle. Overall, it doesn't seem that helpful.