What is the P0412 fault code What is Secondary Air Injection System Valve Shift A Circuit Malfunction? How do you fix the P0412 fault code What are the causes of P0412 fault code symptoms?
What is the P0412 Fault code? What does it signify?
Secondary air injection system valve switches are responsible for controlling the flow of fresh oxygen to the exhaust system. The powertrain control unit (PCM) controls this valve. A P0412 code indicates that the secondary air injection pump valve switch circuit “A” is malfunctioning.
The air injection system reduces CO, nitrous oxide (NOx), and hydrocarbons (HC) emissions by injecting air into cold engine exhaust ports or catalytic converters for warm engines. It is responsible for converting hydrocarbons to water vapor (H2O), carbon monoxide into CO2, and vice versa. An older vehicle may have a belt-driven motor, while a newer model has an electric pump. Relay control circuits in electrical systems control the air injection pump and supply electricity to the solenoid valve. The PCM manages this circuit. It also features a check valve, which prevents exhaust gases entering the air pump.
To ensure proper operation of the air pump, the PCM continuously monitors the relay control circuit which activates it. The air pump relay should be commanded “On” The voltage of this control circuit is therefore naturally very close to zero. In the “Off”. The relay’s voltage must be equal to the battery voltage when the command is given. The PCM will set a P0412 code if it detects an unusual voltage signal in this circuit.
The P0412 fault code can affect vehicles of all makes and models, including but not limited to: Mercedes-Benz, Peugeot. Mitsubishi, Toyota. Lexus. Lexus. Toyota. Lexus. Cadillac. Chevrolet. Honda. Saturn. Jaguar. Opel. Volkswagen.
Notice Some vehicles do not have a secondary injection system.
Other fault codes that relate to secondary air injection system include P0410 and P0411; P0413,P0415,P0416,P0417,P0416,P0417,P0418,P0419,P0418,P0419,P0419,P0418,P0417,P0417,P0418,P0418,P0419,P0419,P041F,P044F. P0491, and P0492.
What causes the P0412 Fault code?
The following are the most frequent causes of the P0412 fault code:
- – Damaged, melted or snapped wires or loose connectors to the control circuit of the air injection valve (high circuit voltage means broken wires, and low indicates a shortcircuit problem).
- – Short or open circuit in the solenoid battery supply circuit
- – Switch to the defective air injection system valve
- Control relay for defective air injection pump
- – A defective air injection pump
What are the symptoms of P0412 Malfunction Code?
You may experience the following symptoms if your vehicle has the code P0412.
- – Illumination for check engine light
- – Air injection system pump may not activate
- – An increase in exhaust emissions
- – Rich engine running
- – It smells like exhaust
How do I fix the P0412 fault code?
There are several repairs that can resolve the P0412 fault code.
- Relay to replace a defective air injection pump power relay
- Repairing an air injection valve switch that is not working
- – Replacing a defective air injection solenoid
- Repair or replace any damaged wiring or connections to the relay/valve switch circuit
- – Repair and replacement of wires damaged from the solenoid to the battery
- Repairing an air injection pump that is not working properly
How serious is the P0412 Fault code?
Most drivers don’t notice anything other than the check engine lights coming on. Some vehicles may experience a slight engine jolt during acceleration. The emission control system is directly connected to P0412. This code will cause the vehicle’s exhaust emission tests to fail.
