Incline traction control shudder?

[bentonrover]

Kinda strange thing happens when I'm at a stop light that happens to be on a hill. When the light turns green the truck slowly rolls backwards. Now when I give it gas to go forward up the hill the traction light flashes, a beep sound, and what feels like the abs kicks in. Kinda like some backlash in the drive train? Only happens when I'm coming from a dead stop up hill? What you guys think? 2008 LC 202k miles

 

[FerzLC]

Kinda strange thing happens when I'm at a stop light that happens to be on a hill. When the light turns green the truck slowly rolls backwards. Now when I give it gas to go forward up the hill the traction light flashes, a beep sound, and what feels like the abs kicks in. Kinda like some backlash in the drive train? Only happens when I'm coming from a dead stop up hill? What you guys think? 2008 LC 202k miles

Normal. It is a hill assist that prevents rolling backwards

 

[bentonrover]

Normal. It is a hill assist that prevents rolling backwards

Wow ok. Yota gurus are always thinking. Thanks again

 

[Markuson]

Kinda strange thing happens when I'm at a stop light that happens to be on a hill. When the light turns green the truck slowly rolls backwards. Now when I give it gas to go forward up the hill the traction light flashes, a beep sound, and what feels like the abs kicks in. Kinda like some backlash in the drive train? Only happens when I'm coming from a dead stop up hill? What you guys think? 2008 LC 202k miles

Totally normal.
You’ll often hear a “boing” sound, with beeping, and the traction control light on the dash will briefly light.
Nothing is wrong. Your vehicle is just noting that you are moving backward while in Drive. It can’t “see.” It can only respond.

 

[tacoduck]

If its is hill assist and its designed to prevent backwards roll, then why does the truck roll backwards? I have this same “feature” in my 2015 LX...

 

[bloc]

If its is hill assist and its designed to prevent backwards roll, then why does the truck roll backwards? I have this same “feature” in my 2015 LX...

It needs to roll backwards enough to actually know it's rolling backwards, before it can do anything about it. From the speed-sensing perspective of the tone rings on the hubs you could be going 80mph backwards and they wouldn't know the difference. But as part of the stability control program there are gyros and inertia sensors that have to do their measurements, compare it to those wheel-speed sensors, and determine you are going backwards.. then apply brakes and stop the movement.

I'm thinking it is designed to allow some movement, but not enough that you roll into a vehicle behind you, as long as that person is driving responsibly and not 8" from your bumper.

 

[tacoduck]

It needs to roll backwards enough to actually know it's rolling backwards, before it can do anything about it. From the speed-sensing perspective of the tone rings on the hubs you could be going 80mph backwards and they wouldn't know the difference. But as part of the stability control program there are gyros and inertia sensors that have to do their measurements, compare it to those wheel-speed sensors, and determine you are going backwards.. then apply brakes and stop the movement.

I'm thinking it is designed to allow some movement, but not enough that you roll into a vehicle behind you, as long as that person is driving responsibly and not 8" from your bumper.

Ive almost rolled back into cars behind me before. Certainly alarming.