Volvo D11F Operator's Manual And Maintenance Instructions page 15

General Information 11
7. Customer Assistance
Volvo Trucks North America wishes to assure that the California
Emission Control Systems Warranty is properly administered. In the
event that owners do not receive the warranty service to which they
believe they are entitled under the California Emission Control Systems
Warranty, they should contact Volvo Trucks North America Warranty
Administration, (336) 393-2000. The address and telephone number of
each Regional Office is in your vehicle owner's package. Owners in
need of additional assistance or information concerning the California
Emission Control Systems Warranty may also contact:
Volvo Trucks North America
Warranty Administration
(336) 393-2000