An AIR pump is used on this vehicle in order to lower the tail pipe emissions on start-up. The PCM supplies a ground to the AIR pump relay, which energizes the AIR pump.
The PCM monitors the HO2S voltages to diagnose the AIR system.
During the AIR test, the PCM activates the AIR pump during closed loop operation. When the AIR is activated, the PCM monitors the HO2S voltages and short term fuel trim values for both banks of the engine. If the AIR system is operating properly, the HO2S voltages should go low and the short term fuel trim should go high.
If the PCM determines that the HO2S voltages for both banks did not respond as expected during the tests, DTC P0410 sets. If only one sensor responded, the PCM sets either a DTC P1415 of P1416 to indicate on which bank the AIR system is inoperative.