P00b7 - SOLVED - Coolant Flow Low/Performance - surge tank cap was defective

What is the meaning of P00B7 and what the cause and how I can fix it.

Its an Engine Coolant Flow Low/Performance. The cause is the surge tank cap was defected and let the coolant throw outside until the coolant level became low.
I solved the problem.

Thanks for the update. I edited the thread title to let others know.