The Check Engine Light being on causes the vehicle to fail emission testing. The air injection pump system is to help lower the emissions coming out the exhaust and can cause the vehicle to fail emission testing. Not checking the air injection pump power relay for burnt wire connections before replacing a bad air injection pump or air switching valve Not checking for proper battery voltage above 8 volts to the air injection pump before replacing the pump for no air pumping out of it
Tests the air injection switching valve is controlling the air injection pump operation during testsĬhecks the resistance of the air injection pump and air injection switching valveĬhecks the air injection pump for proper voltage between the pins of power and groundĬommon mistakes when diagnosing the P0412 code Scans codes and documents the freeze frame data in order to verify the problemĬlears the engine codes retest the air injection system for proper operation How does a mechanic diagnose the P0412 code? The engine may not have any drive symptoms except a check engine light is on. The air injection system pump may not come on. The Check Engine Light will be illuminated and the code is set in ECM memory and freeze frame.
The ECM sets the code from diagnostic inputs from the air injection system driver. The air injection switching valve voltage is too low indicating an short circuit. The air injection switching valve voltage is too high indicating an open circuit.
Toyota camry ecu diagnostic code po402 driver#
P0412 is an OBD-II generic code that the engine control module (ECM) got input from the air injection system driver that the air pump or air switching valve has malfunctioned with an open or short circuit. Secondary Air Injection System Switching Valve A Circuit Malfunction What the P0412 code means