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VERUS PRO Training Module 7
Applies To: VERUS® PRO
Functional Tests: Scanner Functional Tests, Scanner Output Controls, Actuator Tests, Custom Data List
Welcome to Snap-on® Training Solutions®. This module is designed to help you get the most out of your VERUS PRO diagnostic tool, and covers the use of scanner functional tests.
Functional Tests are a great way to isolate the cause of a problem between the controller, a component, wiring or other issues. Functional tests let you override the vehicle controller to take control of a system and determine if the vehicle responds properly or not.
Scanner Functional Tests
Let’s start in the Scanner main menu, Select Engine
Functional Tests are a powerful companion to Troubleshooter which often refers you to perform a Functional Test to verify a suspected issue. Functional Tests can be accessed from this screen.
Let’s go back to Troubleshooter to see how this works.
As an example, we will use the injector balance test. Let’s begin by reviewing the description of this test. From the main scanner menu, select Troubleshooter, Engine and Tests & Procedures.
Select Functional Test Descriptions to see a list of available Functional Tests. Select Injector Balance to see a description of what the test will do for us.
Troubleshooter tells us how to perform and interpret the test. Now that we know what to expect, we can either simply click the button to start the functional test, or click the exit button twice to return to the main menu.
From Main Menu select Functional Tests
Select the Injector Balance test
The next screens give us step-by-step test instructions.
Select each injector one at a time to disable it and compare the RPM drop between injectors. If you are using a fuel pressure gauge in conjunction with the test, compare pressure drop between cylinders. Select an injector once to deactivate and again to activate. This is known as a Toggle Test.
Scanner Output Controls
Other useful types of functional tests are Output Controls, which monitor live output data from the vehicle while you activate vehicle components. And Actuator Tests which check operation of devices like solenoid valves, motors and relays.
A good example of a powerful Output Control is the AC Relay Test.
Select the test, the AC Relay control shows at the top of the screen and the live data parameter view opens. By using the functional test and selecting ON, you are overriding the controller. If you command the relay to turn ON and it does not activate you’ve just eliminated the controller from the possible causes. This pinpoints the likely problem to the relay or wiring. In order to choose relevant data parameters to monitor, use the Change List button to open the Data Menu.
Select the data group Accessory, Electrical, Theft Data.
Custom Data List
Let’s view data parameters relevant to the AC Relay Test. Tap Custom icon on the menu.
First use the Deselect All icon to deselect all parameters.
Select just the parameters you want for your diagnosis. To perform the AC Relay test we will select AC-related data – AC Relay Request, AC Relay On Off, AC Clutch, and AC Pressure. Press OK to view your selected parameters.
This will speed the data refresh rate to help you catch short intermittent glitches. Here's your Custom Data list. Now you can observe the vehicle data response when you command the AC relay On and Off.
Last Updated: August 13, 2020