I have a 2001 S80 2.9 with ~60K miles. I have been getting the message "Engine System Service Required" along with the cruise control working intermitently and the transmission having difficulty finding the correct gear between 50 and 55 mph. The message would be on for a few days then off for a few days. I took the car to a local and reputable Specialty Volvo Service Garage. No error codes could be found. They suggested replacing the ABS module. I bought a rebuilt module from BBA and had it installed.
No change in the symptoms or the message coming on and off.
Any suggestions????
Thanks

 

There should be codes are they using a generic scanner to read it?
If so it most likely wont read the codes you will need a proper scanner to read them.