2002 Chevrolet Avalanche Owner's Manual - Page 341

Engine Air Cleaner/Filter The engine air cleaner/filter assembly has an air filter restriction indicator that lets you know when the engine air cleaner/filter is dirty and needs to be serviced. The air filter restriction indicator is located on the air filter assembly cover. See "Engine Compartment Overview" in the Index for more information on location. See "Owner Checks and Services" in the Index to determine when to check the air filter restriction indicator. The service window (A) with the percentage scale shows the amount of engine air cleaner/filter life used. After changing the engine air cleaner/filter, press the button on top of the air filter restriction indicator to reset it. Your engine air cleaner/filter is located on the front corner of the engine compartment on the passenger's side of the vehicle. See "Engine Compartment Overview" in the Index for more information on location. When both service window (A) and service window (B) turn orange, replace the engine air cleaner/filter. 6-18