2006 Subaru Impreza Owner's Manual - Page 144

Intercooler water spray switch (WRX-STI) NOTE Instruments and controls 3-31 Pressing this switch causes water to be sprayed into the intercooler. It can be used to help maintain adequate intercooler performance when the outside temperature is high. Do not press the switch when the warning light is illuminated. If the switch is kept pressed when the tank is short of water, the water pump motor could overheat. Water is sprayed for approximately two seconds every time the switch is pressed and then released. 300325 The intercooler water spray warning light comes on when the water level in the tank has dropped to the lower limit. If the warning light illuminates, refill the tank with water. The tank is located on the right-hand side of the trunk. For the tank refilling method, refer to the “Intercooler water spray (WRX-STI)” section in chapter 11. In cold weather (when you do not use the intercooler water spray), keep the tank half-empty or below in case the water freezes. A larger amount of water could break the tank if it froze. B00462