Ken

On pre 2005 Volvo's the CAN bus is only routed to the diagnostic connector (6 & 14 High Speed, 3 & 11 Low Speed CAN) once the CAN gateway in the CEM has been told to close the diagnostic relay via an ISO command sent down the K line on pin 7. This is all done but by the diagnostic tester that you plug in.

I guess you will need to get into the CAN network on the other side of the CEM. Perhaps someone else has had more experience of these problems on this car.

HTH

Sean