My 2004 XC90 had the check engine light on with several codes related to the yaw speed rate sensor. The Anti Skid Service Required message was also displayed. I pulled the sensor out and found the connection to be corroded. I cleaned the pins and reconnected. The codes disappeared but the Anti Skid message is still displayed. Any suggestions on a way forward. There does not seem to be any problem driving the car.

 

you need to see if you can find a fully featured OBD2 scanner or a shop with VIDA-DICE to view then clear the codes. If the codes return, then you know what else needs to be fixed. Not all ODB2 readers can do the chassis/ABS codes or the proprietary Volvo codes.