A common issue with GM, VW and Audi vehicles are air injection flow codes like p0410, p0411, and p0412.
If you check engine light is on with any of these engine codes then in this video I will show you one of the most common faults when it comes to air injection codes and how to check if your air pump is working. I have personally seen my fair share.
Pocket Scan Tool: https://amzn.to/2GDzc2z
VW Air Injection Pump: https://amzn.to/2uRuaym
The one tool every mechanic should have: http://amzn.to/2FN2r70