F 350 4WD Super Duty V8-6.0L DSL Turbo VIN P (2004)
Air Filter Maintenance Indicator: Description and Operation
Electronic Air Filter Restriction Gauge
Air Filter Restriction Indicator (F-Super Duty)
F-Super Duty vehicles are equipped with an electronic air filter restriction gauge located in the air cleaner cover on the clean side of the air filter. The
sensor is hardwired to the instrument cluster. When the air flow in the air inlet system reaches the maximum allowable restriction limit, a switch closes
and the filter restriction indicator illuminates.
The condition should be verified by inspecting the underhood air filter
restriction gauge; the warning light is only a secondary indicator. Always
use the underhood air filter restriction gauge to determine when the air
filter element needs to be changed.