Erratic/Malfunctioning ABS unit?

[steamboat26]

I bought my car a little over a year ago, and whenever i have to stop all of the sudden (really jam on the brakes) i can hear my abs unit working (kind of a buzzing sound on the passenger side under the hood) and it won't disengage. It keeps buzzing even after I turn off my car and then causes the ABS warning light to come on the dash, which I'm assuming is a malfunction. The only fix I know for it is to unplug the ABS and then plug it back in a few minutes later.
Is there anyway to fix this without replacing it? Or is this to be expected on a 13 year old antilock braking sensor?

[jey]

Maybe you can check the condition of your brake fluid. It does sound like a wheel sensor has gone bad - you'll need to pull the code from the ABS computer to figure out which one though.

[steamboat26]

thanks i have an OBDII code reading device. do you know if that can be used to find ABS codes?

[97legacygt]

You can read the ABS codes depending on what scan tool you have. Some of of the cheaper models can't read anything but Check Engine lights.

[jey]

I didn't think the Subaru ABS computer passes codes to the ECU, you have to read them directly from the ABS computer I think.

[rad rex]

I posted a thread on how to pull the codes from the ABS computer over on the DIY forums

[steamboat26]

thanks for the suggestions guys
i'd try to read the code using the wire next to the gas pedal, but i'd rather not risk messing anything up.
My ABS sensor engaged today so I unplugged it and now even when I plug it back in, it still makes the grinding/buzzing noise that emanates from the ABS controller/sensor.
I'm just kind of at a loss for what to do at this point, I don't think my car can pass inspection with a nonfunctional ABS unit in VA. Thanks for any other help.
EDIT: I read about some problem spots for 2nd gen leggies and apparently the ABS relay which goes to the hydraulic motor and the hydraulic motor itself are prone to failure and erratic operation. Hopefully replacing the relay will fix the problem.

[Navi271]

So my car has been doing that exact same thing recently. The ABS light comes on and that strange buzzing noise stays on when the car is on, off, driving, idling and such.. It's only happened to me twice now. I think the cold is messing with it.
All I have to do is turn off the car. Unplug the top plug for it. Then restart the car. I've been able to plug it back in now and there is no more buzzing crap. The ABS light will still be on and the ABS will not function. One more turn off and restart and then it works!!

It seems that the ABS just needs a restart, but since that thing buzzes constantly you have to restart the car with it unplugged once. I am still a little concerned because it just started happening this year and has happened twice in one month (december). The extreme cold does tend to wreak havoc with cars though. The ABS still currently works to this day.. So that's a problem for another year

Good luck with it!

[JDMLegacy]

I have problems with my abs to, not that it stays on but it leaks fluid and then gets air in the line, then DOESN'T WORK, while researching my problem, I've read tons of stuff about the abs units being faulty and some of them were recalled you may just need a new unit, there not to expensive from the junk, like 75 bux

[steamboat26]

I have problems with my abs to, not that it stays on but it leaks fluid and then gets air in the line, then DOESN'T WORK, while researching my problem, I've read tons of stuff about the abs units being faulty and some of them were recalled you may just need a new unit, there not to expensive from the junk, like 75 bux

i read some of your thread on the ABS issue. Is it just a direct bolt in plus the lines for power etc? Or is installation and removal more complicated that that?
Also, I've read about recalls for 2nd Gen legacy's, but I've never seen anything about an ABS hydraulic motor recall, just that particularly on the 95, its been prone to failure but wasn't recalled. Do you know if there was an actual recall?

[1-3-2-4]

I have this problem no buzzing but my abs light blinks until I put my foot on the brake.. I have not pulled the code for it, is it flashing the code when you have the car turned to on?

[steamboat26]

I have this problem no buzzing but my abs light blinks until I put my foot on the brake.. I have not pulled the code for it, is it flashing the code when you have the car turned to on?

I never actually pulled the code using the method rad rex posted in another thread, but mine never blinks, when the issue pops up my ABS light comes almost immediately, and lights up and stays solid when I turn my car on and the hydraulic unit is still buzzing.

[1-3-2-4]

wow.. sad to say I had this same issue.. I actived the ABS this morning and I parked at home and about 6 hours later I went out to my car to unlock it and the first thing I noticed was I did not hear the other doors unlock so I was like ok...

I put the key in and turned the car to ON and nothing dead!!! Not knowing it was the ABS pump I buy a new battery and hook it up and the damn ABS pump starts running again!


found this here...

"Brakes: Some of the ABS (antilock brake system) hydraulic motors were faulty, causing them to run intermittently even after the key is turned off. (1995-98)"

http://consumerguideauto.howstuffworks. ... gacy-2.htm (http://consumerguideauto.howstuffworks.com/1995-to-1999-subaru-legacy-2.htm)