They probably meant the wheel sensors, bolted into the brake-backing plates. Most often they can be cleaned by directing a water spray at them from a garden hose.

My problem was the abs module itself. It cost over $400 just for the part. You can probably install it yourself. There was a backorder on these three months ago (which in itself tells you something about these units at a certain age in these cars-mine is a '98 S70 with just over 50K on it)! They can be located on the web used, but that could be risky, considering that the prices I've seen are $225 to $300-- and I've haven't looked recently).

Probably ought to check those connectors and crimped connections that other fellow talked about first, otherwise you're looking at some serious money to correct this problem).

First it was my ABS, now it's a problem with the Air-Bags. This is getting to be an expensive car!