DTC P0410: Air System: Description

AIR system is used to accelerate the heating process of the catalytic converter by introducing outside air into exhaust manifold. Air pump operates on cold engine starts when catalytic converter is least efficient. AIR system consists of air pipe/hoses, air pump, air pump relay, air pump solenoid, check valves, shutoff valve and PCM. PCM controls ground for air pump relay coil, which turns air pump and air pump solenoid simultaneously on and off. With engine running and air pump commanded on, manifold vacuum is allowed to pull up on shutoff valve. This allows pressurized air to flow past check valve to exhaust manifold. Check valve is a one-way valve used to keep exhaust gases from entering air pump. During DTC diagnostic, PCM will wait until certain engine parameters have been met with vehicle in decel. PCM will then command air/fuel ratio slightly rich and turn on air pump relay for a certain length of time. When this occurs, Heated Oxygen Sensor 1 (HO2S1) should indicate a lean condition/low voltage. DTC sets when PCM commands AIR system on during a deceleration and HO2S1 signal does not indicate a lean condition.