2008 Highlander ABS Noise and Violent Action

hlsport08

This title says it all I guess. The one major issue I have had with my 2008 highlander is the ABS in ice and snow.
On a slippery surface, the brake pedal moves up and down violently and there is a terrible noise. The worst part is that the vehicle doesn't seem like it's going to stop at all.
On a phone call to the dealer they said it was normal. The ABS on my Chevy isn't like that.
Anyone have this issue?

kharris

I've only had my 2009 for a few months so I haven't yet used it in ice and snow, but I assume you know that there is a switch to disable the ABS (and also the VSC if needed) when you wish to. You might want to try that when you have a problem.

wwest

Sorry, SOP, Standard Operating Procedure.

I have of recent times campaigned for ABS to remain disabled unless VSC indicates that the vehicle is not following the desired direction. It is well proven that on the type of surface you describe locked wheels will result in quicker/shorter stops.

But until the advent of VSC there was no way to differentiate so the optimum design remained ABS activation regardless.

wwest

No, the switch can be used to disable TC, Traction Control, and subsequently VSC, but not ABS. ABS can really only be disabled via pulling the ABS pumpmotor fuse.

NOT really adviseable at any time but certainly so during the winter months.

steveayz

I've had current generation HL since August of 2007 and had been through 2 winters on it. ABS works very well on my car. There is some pulsation felt on the brake pedal when ABS is engaged but nothing out of ordinary. Take your car to a dealer and have ABS checked out. Also see if your tiers are suitable for winter driving.

hlsport08

Thanks for that input. There was another reply stating that this was SOP, but I just can't help but think they are just experiencing the normal pulsation, etc. that comes with ABS. This seems really unnatural. I plan to go to the dealer when it is icy. The tire situation may also be an issue. My A20s have been less than desirable for slippery weather. I am planning to go with H/T's within a few weeks. This winter should be the test of that.
Thanks.

hlsport08

Hi - thanks for your response. I do think that replacing my A20 tires may help this winter, creating some more bite for the ABS on the icy surface. But I'm experiencing ABS like on no other vehicle I've owned. THis is very unnerving. Lot's of noise coming from under the hood and violent pedal movement.
You may be right - I hope not!

wwest

Lots of improvments in ABS over the years, higher on/off rate, better detection(FASTER processors) of "impending" lockup, continuing operation all the way down to "zero" speed (seemingly), etc, etc. One a really slippery surface, ice rink like, it seems the vehicle will NEVER stop.

Hard to describe the sound except "scrunching".