Question about traction control when starting on an uphill

[bmccall]

Hello, 200-lovers! My husband and I have a 2009 LX570 which we've been enjoying for almost two years. We currently live in the midwest, but are relocating to Vermont. When we visited there last month, we were alarmed by what seemed an unusual behavior when starting from a stop on steep (uphill) slopes. The vehicle made some loud repeated clicking-like noises, evidently part of the traction control system. When it first happened, my husband thought something was wrong with the truck and slammed on the brakes, but the same thing happened a number of times in a row.

We came to think that perhaps this is "normal" behavior and doesn't indicate any problem, as when we ignored it and just accelerated the truck drove just fine. But it was still alarming.

Can any of you who live in hilly places help reassure us flatlanders? [Or, alternately, give us a clue what we should try to "fix"?]

Thanks!

 

[Blackbirdaerial]

Sounds like that’s ‘hill assist’ kicking in so you don’t roll back. It sounds terrible.

 

[bmccall]

Sounds like that’s ‘hill assist’ kicking in so you don’t roll back. It sounds terrible.

Thanks, Blackbirdaerial! It's good to hear that this "terrible" sound is normal.

However, this has happened even on paved or concrete roads, and not at super steep grades. Do you think that suggests that I have some kind of problem, either with my truck or my tires? It seems odd for a vehicle that's supposed to be so robust to be having this "trouble" on paved roads!

Thanks again...

 

[CharlieS]

I live in Vt and haven't seen this on a 13 or a 16 land cruiser. Something sounds off.

I think I know the sound/feeling, I've had it rarely pulling into the garage once or twice when it was slippery wet. I think it may be traction control trying to avoid wheel slip/spin.

Are you easing off the line or punching it? Drive nice and mellow and see if it goes away.

 

[bmccall]

Hi Charlie, no we weren't punching it at all...tried starting as slowly as we could, and it consistently made the noise. And it's happened on bone dry pavement and concrete. When we didn't chicken out and slam on the brakes, and just persisted in slowly accelerating, the truck moved just fine despite the noise...so I'm pretty sure you're right that it was the traction control. But why would it need traction control on favorable (if slightly steep) terrain? Does this indicate a problem with our tires, or with the traction control system?? Thanks!

 

[Blackbirdaerial]

I still think it’s the hill assist. Maybe take a video of it happening and post to be sure.

 

[bmccall]

@Blackbirdaerial after doing some reading, I think you're right! There is a feature called Hill-start Assist Control on at least some Lexus models that is supposed to reduce backward rolling when switching from brake to accelerator uphill. Someone on another forum (for a GX) described it as being ABS-like...which I think is spot on. Presumably this feature isn't present on the LC, which is why @CharlieS hasn't experienced this!

Thanks for offering this reassurance!

 

[Blackbirdaerial]

@Blackbirdaerial after doing some reading, I think you're right! There is a feature called Hill-start Assist Control on at least some Lexus models that is supposed to reduce backward rolling when switching from brake to accelerator uphill. Someone on another forum (for a GX) described it as being ABS-like...which I think is spot on. Presumably this feature isn't present on the LC, which is why @CharlieS hasn't experienced this!

Thanks for offering this reassurance!

I have an LC. It is present. Glad you got it figured out.

 

[lx200inAR]

Definitely normal and happens anytime truck rolls back more than a few inches. If you engage crawl control in the first or second speed, it will sound the same. If that checks out, then it’s working normally. My LX also beeps when it engages.

the end of my street is very steep, so mine engages almost daily.

 

[kcjaz]

Toyota normal. Tacoma’s do it too.

 

[CharlieS]

I can only speculate that they've improved the technology in later years. I drive all kinds of steep, hilly, dirt roads all over Vermont (on and off road), and don't see this behavior.

 

[kcjaz]

I can only speculate that they've improved the technology in later years. I drive all kinds of steep, hilly, dirt roads all over Vermont (on and off road), and don't see this behavior.

That is probably true. My 2013 LC definitely sounds like crawl control is on when I start from full stop on any fairly steep hill. My driveway triggers it. There must be something with the way the transmission works / is set up that makes the truck roll back so bad when in drive compared to other vehicles with autotrans. Our Rav will also do this but it takes a much steeper hill and the noises are not as bad. Maybe that is just due to it not weighing 8000 lbs.

 

[Bunga]

My 16LX does it very rarely. I had read it had the feature, but it almost never actuates. It also never beeps. I have to be up on a very severe angle, then it works great. I was a passenger in a Tacoma and it did it all the time but usually backing.