PO412 Air System Switching Valve Circuit

Last week the Check Engine Light came on so I checked for trouble codes with my scan tool and got the PO412 code. I erased the code and a week later it came back on. According to my research, the Fix is: 1) Air injector pump and 2) Oxygen Sensor.

Questions:
1) How can I check the Air Injection Pump with my multimeter?
2) Where is the Oxygen Sensor located and is there more than one?

 

To check air pump usually when you turn on the engine when is cold usually you will hear pump noise running by open the hood, the other way by take it out the pump and hot wire it from battery.

For 02 sensor is it bank 1 or bank 2?

 

That code is a circuit code for the Secondary Air Injection Switching Valve, it means either the wiring between the Air Injection Control Driver module and Switching Valve is open or shorted or the valve itself is open or shorted. It has nothing to do with the pump nor the AFR or O2 sensors.

 

Update: I replaced the air switching valve (also called purge valve?) that is bolted to the top of the intake manifold and has 1 electrical connector and 2 hoses. I used an OEM part from Toyota. I cleared the code and the Check Engine Light hasn't come back on yet.

 

The Air Switching Valve and Purge Valve are not the same thing, the Purge Valve is part of the EVAP system and the Air Switching Valve is part of the Secondary Air Injection System.

Anyway glad you got rid of your CEL.