Active Test

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📖 YOUCANIC Automotive Glossary

An Active Test is a scanner-controlled function allowing you to command specific components to activate on demand — turning on the cooling fan, cycling the EVAP purge valve, firing individual injectors, operating the EGR valve, activating the fuel pump, or engaging the A/C compressor. Instead of waiting for the ECU to activate a component during driving, you force it to operate from your scan tool. Active Tests require a scanner with bidirectional control — basic code readers cannot perform them.

Active Tests are invaluable for confirming whether a component physically works after a DTC points to a specific system. For example, with P0401 (EGR Insufficient Flow), commanding the EGR valve open while monitoring vacuum immediately verifies valve operation. After replacing a component, Active Tests confirm proper installation before reassembly. The YOUCANIC UCAN-II provides Active Tests across engine, transmission, ABS, and body systems. Always ensure the vehicle is safely secured — some tests move components unexpectedly.

Synonyms:
Actuation Test, Component Test, Output Test
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