I found a thread about the same problem I am having but I didn't see any way to reply to it so sorry for starting a new thread on the same topic.
Anyway, the problem is the ABS brake fault light came on and there was a buzzing sound coming from the black plastic box on top of the ABS brake control unit even with the ignition key turned off. I disconnected the battery, opened up the black plastic cover and removed the relay. It has five contacts on it. I tapped on it an reinstalled it and reconnected the battery and the problem has gone away, at least for now.
Someone on the other thread mentioned they couldn't find a place that sold the relay. I found a company called Parts Geek that has it for $37.78 in case someone needs it. Maybe someone knows some other place that sells it cheaper.
http://www.partsgeek.com/gbproducts/WC/ ... oogle+Base

junkyard is free and if they charge you its very cheap lol and you can get alot of them if there a few j30s

You need a new relay. They use to be dealer only. If you found another source that's good-do tell.

I just smack mine with my leatherman if I hear the buzz. (The case its in)
Need to replace it though because it WILL drain your battery if you let it buzz overnight.

Followup to my previous post on the ABS relay problem. After five months the problem of a buzzing sound coming from the ABS relay box after the engine was shut off, and the ABS fault light being on got worse to the point where the temporary fix of banging on the relay didn't work anymore. I called a dealer and they wanted $66 for a new relay, and an online vendor wanted $42.
So i went to pick your part and bought three of them for $2 each (half price sale day) plus $2 to get in, just in case one of them didn't work. Some other model infinitis also use the same relay if you can't find a junked J30. The relay that actually causes the buzzing sound problem (sound is actually coming from the ABS motor) is the one with the cross on top and has four terminals on it that controls the ABS motor and causes it to constantly run, draining the battery. The other relay under the plastic cover controls a solenoid and has a flat top and five terminals on it.

I don't know which of these is the part number, but all three numbers were on the motor actuator relay case.
11200010050
ACB32201 C01
CB1of-12V

These are the numbers on the solenoid actuator relay:
11200020020
ACB12201A02
CBiF-12V

It is easier to pull the ABS motor control relay out if you pull the other relay first so you can get a better grip on it.

While I was there I also got a dashboard dimmer control switch for $3.50. Takes only about a minute to pull out.

i have a tool bag with an inner pocket and just pocket small switches and grab lots of interior clips and stuff when i go to pull a parts here in atl