I have an issue that I think covers multiple failures.

Ocassionally while driving and coming to a stop, the last 2 or 3 feet the ABS indicator comes on and the brake pedal drops about an inch or two. No pulsing feedback from the ABS. Most of the time when this happens the ABS INOP comes up. This is for normal stops like a grandma would do, coming to a stop light on dry pavement. It usually surprises me too, and when the pedal goes down the stopping distance suddenly increases. It is almost always under 5 mph when it happens. My tires have plenty of tread, and there is NO sliding of any wheel, I mean this is a SLOW speed problem.

I read an old post (I DO try to search before posting, but I also MISS stuff) where the differential sensor maybe bad. The car is the 1995 in my sig.

I checked the grounds and the wires where I could get to them and everything seems solid. Fuses and relays are intact, as is the 3rd brake light.

I am going to put new calipers/rotors on tomorrow, while I have it jacked up is there anything I need to look for? Is there any way to test the diff sensor?

 

I have that same issue right now. It seems like the front abs sensors are built into the hub so not sure what you can clean there other then the contacts and the connector plug. Not sure about the rear sensor on the differential housing. I haven't looked for that one yet. If you find it post some photos.

 

My car did that, too when it was only a few years old, and reseating the connectors seemed to fix it. It did it more than once. If that doesn't get it going for you, it still might be the problem area. My car was pampered and never saw bad weather so who knows about a 17 y/o car that has been driven in all kinds of weather.

I thought it was irresponsible for GM to design it that way - when it fails, the pedal goes to the floor and it doesn't stop when you need it to - it moves ahead a few feet of where it would normally have stopped. It doesn't fail safe - . If I'd have hit something or someone because of it, I'd have sued them.

 

When I had that problem, is was due to the rear sensor on the diff housing. But it's a Strange 12-bolt, so it has a Strange sensor, which requires manually adjusting the clearance to the reluctor. But the symptoms were the same, sudden extended stopping distance on low speed stops.

I'd pull the rear sensor out and try cleaning it. Might have some metal particles sticking to it.

For Wilson, the sensor is on top of the center differential housing. Shoebox has a photo showing the location.... look at the far right side of the photo:

http://shbox.com/1/fuel_pump_wiring.jpg