I have had same ABS issue. You can read other posts. I just replaced the ABS in my 99 S80 because the dealer told me the codes indicated that it needed replacing. (I did it myself.) I received a "Check Engine" light right away that cleared the next day. Unfortunately, the ABS light has come back on once since the module was replaced. Someone recently replied to me that it was likely something else. This person was correct. I am unsure of the dealer's honesty and/or ability. My assumption is that if it was the modeul as the dealer indicated then the problem should be gone. Since the ABS light returned, it may not be gone. Hopefully you problem is the module. I'd get there right away so that if the problem returns, you've got time to respond while under the warranty. Dealers like this type of problem anyway because they don't have to think. Thinking is often their main weekness anyway. They LOVE to replace parts and then blame the computer if they are wrong.