Welcome to Snap-on Training Solutions. This module is designed to help you get the most out of your VERUS EDGE diagnostic tool, and covers the use of scanner functional tests.
Functional Tests are a great way to isolate the cause of a problem with the controller, a component, wiring or other issues. These 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 System menu, Select Engine.
Functional Tests are a powerful diagnostic feature that can be used to verify the operation of a suspected component.
Let’s see how these tests can be used to verify component operation. To get started, select Functional Tests.
Select Injector Balance. The next screens give us step-by-step test instructions. Select Continue.
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
Actuator Tests
Another useful type of functional tests is an Output Control, which monitors 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 vehicle 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 the 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.