2008 Toyota Yaris Owners Manual - Page 670

4-3. Do-it-yourself maintenance n Checking interval Inspect and replace the air conditioning filter according to the maintenance schedule. In dusty areas or areas with heavy traffic flow, early replacement may be required. (For scheduled maintenance information, please refer to the "Scheduled Maintenance Guide" or "Owner's Manual Supplement".) n If air flow from the vents decreases dramatically The filter may be clogged. Check the filter and replace if necessary. NOTICE n When using the air conditioning system Make sure that a filter is always installed. Using the air conditioning system without a filter may cause damage to the system. 254