The car engine of injection between years 1990 and 2008 have a valve to control the idle speed. This valve is called IAC (Idle Air Control) or commonly called stepper motor.
This valve is a common fail cause.

The car engine of indirect injection have coil based injectors, they split in two big groups: High and Low impedance.
This device can test almost all IAC valves and Stepper of car industry, both groups of injectors.

Is the tool more easy to use of the market.

Manufactured for hard work, with a high endurance.
The device test multiple IAC types ( Steppers, PWM, Continous current etc)
Is a elemental tool for any modern mechanic and avanced users.