Oh, maybe I am reading that wrong. When the abs activates, it can feel like it is pulsating and will sound like grinding sort of as the brakes do "pulse" when the ABS is active, so that may be normal. But...if your "ABS Inop" light is ON, that means the ABS system is inoperative. You will still have braking, but no antilock braking, so you should not feel any pulsing or hear anything. Do you also have the red "Brake" warning lamp on?

 

no the red brake light does not come on. when the abs inop light is on i get the pulsing and grinding noises. when the abs inop light is not on the brakes feel fine. also when the abs inop light is on and i brake the car feels like it doesnt want to stop. i have to press the petal more to stop when the light is on versus off, as if only the front brakes were wroking.

 

abs unit is failing. my truck did the same thing. had gm shop test and replace.

 

@craby is that the motor pack or the ebcm.

 

it was several years ago but i think it was the motor pack. best to have it tested on abs machine.

 

will do i allready called to see how much it is. 135 just to pull the codes

 

if you have any try callin a couple more shops.

 

MYSTERY BRAKE WARNING LAMP ISSUE SOLVED!!!!!!!!!!!!!!!!!!!!!!!! (I thought....)

Turns out it's the aftermarket alarm system I had installed is causing this....somehow. I still got to dig into it more......IF I get in and start the car right away, brake warning lamp stays on all the time. IF I get in the car, turn the key to run (not start) and let the doors lock (this was done when they installed the alarm system because they didn't use to lock automatically), then start the car, the brake warning lamp goes off and on as it should with the parking brake. So, it is electrical somehow. I do know they had to install like 5 extra relays when they installed the alarm (because I had to pay extra for the extra relays), so apparently something is messing with the brake warning lamp circuit if I start the car BEFORE the doors lock. I also removed the ABS Inop bulb so that problem has gone away as well : ) It's nice finally driving this car without stoopid idiot lights on the dash being lit up....lol

Two days now, multiple starts...as long as I let the doors lock before starting, the light stays off.

 

Crap. Light came back on..grrrrrr

 

Got my factory service manuals. Was able to use the troubleshooting charts and determine the problem to be the EBCM. Went to the pull a part and they has a 94 v6 camaro, snatched the EBCM out of it for $15. Swapped it out and voila, no more brake light. (except when I have the parking brake on). But what a pia to get that thing in/out....especially with a manual (clutch linkage is in the way)