The warning lights come on intermittently, several times over a week, usually preceeded by a grumbling noise from the ABS System. I took it to a garage, where they diagnosed the system with the computer, and they concluded that a connector was corroded, that solved the problem somewhat, as it now comes on much less frequently. Is this a serious problem, what should I do, I was going to take it back cause they charged me $100 to clean the connectors!