If there were no codes for the engine your check engine light may be triggered by a missing speed signal from the ABS Control Unit.

Do you know if the tool that was used is capable of reading ABS codes? Only a few tools (The very expensive ones) are able to read ABS codes on Volvos.

In any case, most likely your ABS Control Unit has failed. All of them will eventually fail after they reach 80,000 miles or 5 years.
Reading the ABS codes costs about $125.00 at the dealer and about 95% of the time, the diagnosis is a defective ABS Control Unit.

Here's information I have on this subject.
Vitor's ABS Website
Click on the ABS / TRACS Link