RRocket

My ABS are activating at nearly every stop. You can hear and feel the pulsing of the system. This occurs when braking normally in everyday driving. I can't imagine my brakes are locking up, therefore I would guess it's possibly a wheel speed sensor acting up? If yes, how do I diagnose which one?

Any other ideas are appreciated.

Thanks!!

iToaster

The system should diagnose a bad sensor on its own and turn on the ABS light. Are you sure the pulsing isn't due to warped rotors?

nezlyfe

The pulsing in the brake pedal is most likely the rotor being warped. If there is an O' Reillys auto store, or machine shop, have them check and resurface if possible. If you want to check, take the wheel off and put the lugs back on and spin the rotors, neutral for rears, and see if the edge wobbles. Also, check calipers for even pressure and the guide pin is working. And leaks

runyun

iTrader: (11)

pulse or vibration? (like pager)
if it feels like a pager vibrating... guarantee its the brake master.
(more common on 98-00 gs's)

Also, i wouldn't drive your car. Eventually, you will lose all brake assist.
Basically, it will be damn near impossible to stop/slow down your car!

YxUxMADDDD

iTrader: (2)

i don't know if it's the same issue but when i brake, i had to push all the way down and it feels like it's "pulsating" at my foot kinda like it's slipping\skipping to stop. I had all 4 rotors and pads replaced with new ones. still having the same issue. brought the car used with 200k. could it be the axel or something? i'm not use to pushing the pedals in that far compared to my other gs. it's a major difference.

FrankT

verify that your wheel sensors are seated and secured correctly.
Did you buy the car this way; did it happen after the brake job?

DosyBoy

iTrader: (1)

Brake booster might be on its way out...

RRocket

This is definitely not a warped rotor. It's the same pulsing you get when you lock the wheels up on ice/snow/gravel/emergency stop.

No ABS lights are on.

YxUxMADDDD

iTrader: (2)

then me and rrocket might be on the same boat. as for me, i brought the car that way thinking that it was the brakes. come to find out, the right rear rotors were used to the point that the blades sunked in. changed out the complete brakes and rotors HOPING it would go away but NOOOOOOOOOOO.... it didn't. and no abs lights on... unless he pull the bulb out which i have to check cause it seems this idiot used a black marker to cover some warning lights.

kamlung

iTrader: (8)

When you start the car, do you see the self diagnosis work? All abs, vac lights on for a few seconds then off?

Otherwise I'd check for codes and get your brake fluid flushed.

RRocket

Diagnostics work fine. No codes or warning lights. Brake fluid was changed per service recommendation and isn't due yet for another change. Brake fluid would not cause this issue anyways.

I'm still thinking wheel speed sensor or possibly master cylinder?

JLAWS

I had a similar experience. My Gs400's abs would kick in right when it would come to a complete stop. I somehow fixed it by doing the following. Not sure if it was a fluke but I haven't had any more problems since.
First try this, turn you ignition key on all the way but don't start it. Then pump the brakes about 50 times till you hear a beeping sound. Then check your fluid levels and fill if needed. Then drive around to see if the problem went away. If it didn't then take off each wheel sensor and make sure nothing is on them. One of the sensors was caked in thick grease. It might have been affecting the magnetic sensor.
Hope it work out.

RRocket

Just curious...what is this procedure supposed to do? When it beeps is this some diagnostic more or??

I had never heard of this so I'm just wondering what it does and why the beeping.

V8LexGS

Gents -

I recently refreshed my rear suspension with new bushings, toe links, and other items from Mike @ Figs.

When I got the car back from the shop - I had this exact issue. Everytime I stepped on the brakes - and especially at low speeds - I would get full out ABS Activation.

My mechanic tested all the wheel speed sensors - they were dirty like the above post, but tested fine, and work 100% with a cleaning....however, this did NOT fix the issue.

To fix the issue - do a search in the Rx Forums - for "tone ring."
The ABS tone ring is a "gear-like" wheel that sends the electrical impulses to the abs sensor to measure. When the car gets older - the metal in the knuckle rusts, and pushes a metal liner into the tone ring - destroying it.

This makes the ABS sensor read incorrectly - and activates the ABS everytime you brake.

I will say - NO ONE - at all - sells the ring. So if this is the issue - you're going to have to do what I did and replace the entire CV Axle - as the ring is built into it. Also, the metal liner will need to be replaced also - this is approx a $10part from toyota. The real expense is the axle. If you want a new one - it's $500, and they are in very limited supply. When mine went - there was ONE new unit in the whole USA.

I believe this is your issue. Hope I am some help to you.

- V8LexGS

iamkhanz

Any one try this that had these issues?