Equus-3022-manual.pdf Link

Once you download the , do not just leave it in your "Downloads" folder. Optimize it for field use:

If you plug the Equus 3022 into the OBD2 port without turning the ignition on, the device will not power up. However, if you quickly press and hold the “LINK” button while the ignition is off, the unit will draw residual power and display battery voltage on the screen for two seconds. This is an undocumented way to test your car battery without opening the hood. Equus-3022-Manual.pdf