[HudsonValleyTitan]

While in 4X4 mode today in snow, when my drivers side rear tire slipped, it sounded like the antilock brakes kicked in only on that tire. Is that the ABLS working or is there a problem with my truck? It only made the noise while the wheel was slipping quite a bit, not when it had traction.

ABLS (Active Brake Limited Slip) uses the ABS system sensors to detect a slipping wheel and apply the brake(s) to that wheel to help send power to the opposite wheel. On a 4X4 Titan, we have this front and rear. And only in the rear when in 2WD.

 

[2007 TITAN LE]

ABLS (Active Brake Limited Slip) uses the ABS system sensors to detect a slipping wheel and apply the brake(s) to that wheel to help send power to the opposite wheel. On a 4X4 Titan, we have this front and rear. And only in the rear when in 2WD.

So it is normal to hear that noise? I have had the slip light come on before, but never made a noise.

 

[MuskyHunter]

It is normal. That is the design of the system.

 

[HudsonValleyTitan]

So it is normal to hear that noise? I have had the slip light come on before, but never made a noise.

It's your truck so...if it's a new sound you've never had before, have it checked out. What I can tell you is how the system works and what sensors it uses etc. I personally can't say I can actually hear my ABLS working...other than seeing the SLIP light come on, it's pretty much a hidden operation.

 

[jljue]

From what I've observed on my '07 Titan with ABLS and VDC, the slip light only comes on when VDC is enabled and wheels are slipping. I don't recall seeing the slip light when the VDC is off when the wheels are slipping, but do feel the ABLS kicking in to transfer torque from one wheel to the next. I don't recall much noise other than the sound of a wheel spinning and the all of the sudden not spinning while moving.

 

[BigRedTitan]

The only part of ABS that comes into play with the ABLS is the speed sensor(s). You should only hear the ABS sound if the ABS motor is operating to pump the brakes to keep the wheel(s) from locking up.

When my ABLS kicks in due to wheel spin, the slip light comes on and the engine power is cut. Other than this, I never hear any noise related to the ABLS.

 

[loufish]

The only part of ABS that comes into play with the ABLS is the speed sensor(s). You should only hear the ABS sound if the ABS motor is operating to pump the brakes to keep the wheel(s) from locking up.

Well, what provides brake pressure to the spinning wheel when the ABLS is operating?....

 

[BlingAlong06]

that chrome brake distrubution block under the hood is what comtrols the pressure to each wheel

 

[The Pawnbroker]

Should the ABLS cut power at any speed? I can understand when your speed is slow (like being stuck). But it seems to me that it shouldn't cut power at higher speeds. I have almost been in an accident several times already because of this. For example, I have to make a left turn onto a busy high speed street every day. If it is a little wet, I end up spinning the wheels a little and when the slip light kicks in, I loose power and end up not being able to get out of the way. Another time, I misjudged the speed of oncoming traffic (some guy was flying!!). I was making a turn across traffic and punched it and the Slip light kicked in, I lost power, and I almost got t-boned. I think this is really dangerous. The problem is even when I peddle it, it takes too long for the power to kick back in and I end up getting in and out of the throttle trying to get the heck out of the way. Am I the only one?

Thanks,

Dave

 

[skyhammer]

ABLS never cuts your throttle at any speed. It sounds like you are describing what happens when VDC kicks in. VDC can and will cut your throttle as well as apply the brakes to keep you on a straight course.

"The only part of ABS that comes into play with the ABLS is the speed sensor(s). You should only hear the ABS sound if the ABS motor is operating to pump the brakes to keep the wheel(s) from locking up.

When my ABLS kicks in due to wheel spin, the slip light comes on and the engine power is cut. Other than this, I never hear any noise related to the ABLS."

It sounds like you are experiencing VDC also.Turn off VDC and you will left with ABLS and will have no more throttle interference. There is no ABS motor, brake pressure is increased to the spinning wheel through the use of solenoids.
If you engage your ABLS enough, you will definitely notice the ABS unit making noise, in certain situations it is very noticeable.
It is definitely not true that the only role that ABS plays when ABLS in engaged is the speed sensors. The ABS unit is what activates the brakes when ABLS is engaged.If the ABS unit wasn't involved in a major way you wouldn't have ABLS.
If you want to confirm that ABS unit is actually controlling ABLS, put your hand on the ABS unit when the truck hasn't been driven for a few hours, the ABS unit will be cold to the touch. Then go out and spin the tires engaging ABLS for a minute or so, the ABS unit will be to hot to touch.

 

[electricjohn]

I have heard and felt my front brakes (and possible rears too) pulsate when I went into a curve too fast and the truck started under steering on black ice. It was definety the VDC taking over and kept the truck under control. I was not in 4WD at the time or stepping on the brakes.

[edit] Oh and my slip light will come on with the VDC off. Tested it last night on some snow and ice.

 

[skyhammer]

Your slip light should come on with VDC off. The slip light comes on either when VDC engages or ABLS engages or both.

 

[HudsonValleyTitan]

I don't have VDC so power is never cut off on my truck. But....I have heard from others here who do have it that even with the VDC turned off, power is still interupted. To what extent, I don't know.