Chevrolet 2003 Tahoe Owner's Manual page 376

See Part B: Owner Checks and Services on page
6-
IO
to determine when to check the indicator.
The service window A with
the percentage scale
shows the amount
of engine air cleanedfilter
life used. When both
service window A and
service window B
turn orange, replace the
engine air cleaner/filter.
After changing the air filter, press the top button on the
indicator to reset it.
The air cleanedfilter assembly is located on the front
corner of the engine compartment on the passenger's
side of the vehicle. See Engine Compartment Overview
on page 5-74 for more information on location.
5-23