Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Code P0411 means the onboard computer has not detected the expected system pressure after activating the AIR system. This fault could be caused by bad wiring connections or by by a bad pressure sensor, AIR pump relay, etc.
The tool to use for this type of diagnosis is a scanner capable of actuator tests that would allow us to try to turn the pump on and off whenever we wanted to so we could check the pertinent circuits. Do you have access to such a scan tool?
Not necessarily a dealer, there are many independent shops that are buying this type of tools and can handle this kind of repair without charging you an arm and a leg.
The car makers are once again forcing the consumer to go back to the dealer for repairs. It's a shame and, in my humble opinion, a gross abuse of the free market system. Hope for all our sakes someone reins them in soon.