Question about fuel injectors

Hello everyone,

I would like to know the following:
If you have the injectors tested at a Bosch service center, they can only check the first stage. If the first stage is okay, does that mean the second stage is also okay?
I have a 5-cylinder TDI engine with 140 horsepower and the engine code AEL. I mention this so you know which injectors we're talking about.

Thank you and best regards.
Wool.