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Functional Tests
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6.5 Functional Tests
The
Functional Tests
selection is used to access vehicle-specific subsystem tests.
Available tests vary by manufacturer, year, and model. Only the tests available for
the identified vehicle display in the menu.
There are several types of functional tests:
•
Information Tests
—these are read-only tests, like selecting “VIN” from a
Functional Tests menu to display the VIN of the identified vehicle.
•
Toggle Tests
—these tests switch a component, such as a solenoid, relay, or
switch, between two operating states.
•
Variable Control Tests
—these tests command a certain value for a system or
component, such as varying spark timing in 1° increments or EGR valve duty
cycle in 10% increments.
•
Reset Tests
—these tests reset the adaptive, or learned, values that are stored
in the vehicle electronic control module memory.
•
Scripted Tests
—these tests are software routines that place the vehicle into
special operating modes for performing certain repairs, such as bleeding
brakes with ABS.
Selecting Functional Tests opens a menu of test options that varies by make, year,
and model. Selecting a menu option either activates the test or opens a submenu
of additional choices. Follow all screen instructions while performing tests. How and
what information is presented on the screen varies according to the type of test
being performed and the vehicle being serviced.
Figure 6-31
Functional test menu
Toggle and variable control tests often display functional test controls on the toolbar
at the top of the screen with PID data in the main body.
Figure 6-32
Functional test example
Figure 6-33
Functional test example
