ABS unit humming with engine off

[Spideyz]

So the ABS light comes on while my wife is driving around town yesterday. When she gets home, I look at it and I pop the hood with the engine off. The ABS unit is humming like the pump motor is running. Pulled the neg. terminal on the battery and of course it stops. Put the neg terminal back on, humming starts up. Read the ABS trouble code under passenger seat and found number 9 which is: "Faulty motor and/or motor relay or broken or shorted harness circuit." I took off the relay cover on the unit and pulled the relay. Humming continued. Put relay back in... humming continued. Then I pulled the ABS fuse from the main fuse box and the humming stopped. So now I have disabled the ABS system. What is the best way to troubleshoot this problem. My first inclination is to replace the relay in the ABS unit and see, but I hate wasting money if that turns out to be something else. Any advice is appreciated. Thanks. Keith

[Legacy777]

Sounds like you're on the right track. You should be able to test the relay and see if it's working, or possibly sticking.

However if it's not too expensive, it may be worthwhile to replace it.

[SP-Boxer]

Strange, I had the same thing when I just bought my car. But when I pulled the plug (?) it stopt. When I placed it back, it didn't come back.

I had it after an offroad trip, so I guessed it was dirt



Good Luck!

[DLC]

I think this happened twice on my 93. Both times I unplugged it for a minute and it went away.

[Subtle]

Had that humming and it continued after the ignition was turned off.

Pulled fuses until it stopped and despite a lot of experience went to the stealership. They put the diagnostics on and declared there was no problem. By way of entertainment, when it happened the yellow seat belt light on the dash was flashing.

This was before discovering this site, but went to a small shop and when the problem was described the guy quickly concluded the solenoids had failed.

The fix was real easy.