Something weird just happened w/ my ABS on hill

[AUSig]

I was just leaving a shopping center and something really strange happened. I was stopped on a hill, somewhat steep but nothing crazy, and when I went to accelerate I just rolled back and the ABS brakes started clicked. I hit the brakes and tried again and the same thing happened. There was a car right behind me at this point so I gave it a decent amount of gas and was able to pull out. Why would this have happened? I had a 100 series before this 4runner with same engine/transmission and have never experienced anything like this before...

Before someone asks, this was 100% dry pavement. No way any of the tires were slipping. I dont know much about atrac or vsc, but there is no reason it should have engaged.

 

[BlackWorksInc]

Sounds like the Up-Hill Assist was trying to kick in. Its like Downhill-Assist Control but it works to keep the vehicle from rolling backwards when climbing hills. Most people never activate it/get it to happen, its one of the subtle features the 4th gens got (I believe it was carried over to the 5th gen as well) I don't remember if it was ever mentioned in the owner's manual.

I'm a little surprised that your V8 even rolled backwards, I don't think mine has ever rolled backwards even in San Francisco's hills; the torque from the V8 combined with the torque converter stall speed usually means I can just sit at a red light on a hill with my foot off the brake (though if I give it a bit of gas it starts to creep up by itself. )

 

[AUSig]

Sounds like the Up-Hill Assist was trying to kick in. Its like Downhill-Assist Control but it works to keep the vehicle from rolling backwards when climbing hills. Most people never activate it/get it to happen, its one of the subtle features the 4th gens got (I believe it was carried over to the 5th gen as well) I don't remember if it was ever mentioned in the owner's manual.

I'm a little surprised that your V8 even rolled backwards, I don't think mine has ever rolled backwards even in San Francisco's hills; the torque from the V8 combined with the torque converter stall speed usually means I can just sit at a red light on a hill with my foot off the brake (though if I give it a bit of gas it starts to creep up by itself. )

Man I can already tell I'm going to hate the electronics on this Runner once I start wheeling it. My 3rd gen didnt have any of that crap. Is there a way to disable uphill assist???! If it was uphill assist trying to help, it made it worse, I rolled back 3 or 4 feet before I could get it to move forward!

Thats why I was surprised too, I just got this 4Runner 4 weeks ago and it definitely has a very strong idle creep (how do you phrase that?)

 

[CXS]

I don't have an answer for the OP but I've had my Up-Hill Assist engage many times but all have been off-road.

I came from an '88 Land Cruiser and the electronics were hard to get used to but now I love it off-road. Give it time and learn how it works to use it to your advantage.

 

[having fun]

I know it work for up or down hill, great when off roading in my experience. Easier than having to ride the brakes.


Hated it at first, but, love it now.

 

[Bossman]

Sounds like the Up-Hill Assist was trying to kick in. Its like Downhill-Assist Control but it works to keep the vehicle from rolling backwards when climbing hills. Most people never activate it/get it to happen, its one of the subtle features the 4th gens got (I believe it was carried over to the 5th gen as well) I don't remember if it was ever mentioned in the owner's manual.

I'm a little surprised that your V8 even rolled backwards, I don't think mine has ever rolled backwards even in San Francisco's hills; the torque from the V8 combined with the torque converter stall speed usually means I can just sit at a red light on a hill with my foot off the brake (though if I give it a bit of gas it starts to creep up by itself. )

Hill-Start Assist Control (HAC) is a standard feature on 4th and 5th generation 4Runners, designed to assist the driver on a steep incline. The system utilizes electronic sensors within the brakes to detect when a wheel or wheels are slipping, then gently applies the brakes. This allows the driver time to engage the accelerator, thus helping to prevent a precarious backwards roll.

 

[bob3dsf]

+1 for the hill start assist.

Once you get used to the doodads I think you'll find you like them.

e.g: This winter, on a school snow day, I took mine to the nearby high school parking lot to play around on the slick surface and go through all the modes and get a feel for how the ABS and handling respond during poor traction. I'll say that with 4wd engaged and the abs/ traction control engaged I had to try hard to make it slip and spin out, and even then I couldn't get it to spin much. The traction control system is very effective. I gave me a lot of confidence that anytime I need to drive in snow that the truck will perform well (so long as I don't do anything stupid or the other yahoos out and about). I commute 50 miles to work and I've gone the whole way in fresh snow (the firemen have to get to work, you know). I hadn't had any opportunities for that kind of driving yet since having my Runner.

Also, If you lock your center diff. it will de-activate the traction control for times off road when you don't want the abs kicking in for traction... It's a good system.

 

[BlackWorksInc]

Man I can already tell I'm going to hate the electronics on this Runner once I start wheeling it. My 3rd gen didnt have any of that crap. Is there a way to disable uphill assist???! If it was uphill assist trying to help, it made it worse, I rolled back 3 or 4 feet before I could get it to move forward!

Thats why I was surprised too, I just got this 4Runner 4 weeks ago and it definitely has a very strong idle creep (how do you phrase that?)

Honestly for the most part the electronics are really well done in terms of off-road capability. There really hasn't been that many times I have felt the electronics really limiting me off-road, typically only in mud (because of throttle cut-off for the TCS), though I will have to make an "Off-Switch" for them one of these days.

 

[having fun]

I love the way they modified the 08 with the TCS shut off switch built in.

 

[JB.]

I'm a little surprised that your V8 even rolled backwards, I don't think mine has ever rolled backwards even in San Francisco's hills...

Didn't you say once that your HVAC has basically one position -- max cool?

I think that explains it.

I recently did a little test off road. Sitting on a 17 degree hill in low range with AC on, the truck held easily. Turned AC off, instantly started rolling backwards. Those couple of hundred rpms make a big difference.

 

[BlackWorksInc]

Didn't you say once that your HVAC has basically one position -- max cool?

I think that explains it.

I recently did a little test off road. Sitting on a 17 degree hill in low range with AC on, the truck held easily. Turned AC off, instantly started rolling backwards. Those couple of hundred rpms make a big difference.

That's very true... I almost always run the A/C, so I probably never noticed otherwise, will have to try that next time I'm in San Fran.

 

[97BlackAckCL]

Yep, that was just the assist, not your ABS