Either way, the placement must allow it to easily draw in air and direct it into the exhaust stream to help reduce emissions. The pump is usually positioned at the front of the engine with the serpentine belt around it but can be hidden in some vehicles such as behind a plastic front wheel well liner. It decides when to activate the air pump and adjusts the necessary parameters to ensure the secondary air injection system works efficiently.

The engine control unit (ECU) acts as the brain and plays a pivotal role in coordinating all these components (and most other systems within a vehicle).

This safeguard maintains the system’s functionality and prevents damage to the pump. Its primary task is to prevent exhaust gases from entering the air pump.

The combination valve works together with the pneumatic control valve.

By regulating the air supply to the exhaust manifold, it helps complete the secondary combustion process.

The pneumatic control valve manages the airflow in the system.With the help of the engine control unit, this relay makes it possible for the pump to operate efficiently and be supplied with the required amount of air. The control relay is responsible for regulating the electric pump.While the pump is essential, there are other parts that make up a secondary air injection system to help reduce vehicle emissions. Other Components of a Secondary Air Injection System A failure of any of these vital components can result in complete or partial system failure. The engagement of a vehicle’s secondary air injection pump is perceived by these sensors as a lean condition and is relayed to the vehicle’s ECM/PCM.Ī lack of O2 sensor response to secondary air injection pump engagement is generally earmarked as a fault condition, resulting in the illumination of a check engine light.Īlso included within the secondary air injection pump circuit is an air solenoid, relay, check valve, and assorted vacuum lines. Secondary air pump operation is monitored by a vehicle’s O2 sensors. This, in turn, drastically reduces a vehicle’s carbon footprint. The presence of this fresh air assists in converting carbon monoxide into carbon dioxide, and hydrocarbons into condensation water. This additional airflow is used to further neutralize a vehicle’s noxious emissions, especially in conjunction with exceedingly rich operating conditions. This pump runs for approximately 30-120 seconds following start-up and is operated upon electrical request from a vehicle’s ECM/PCM. This is done to offset the naturally rich condition that is created during engine start-up. Modern vehicles feature a specialty secondary air injection pump, which directs airflow into a vehicle’s exhaust stream. Secondary Air Injection Pump Replacement Cost.Can You Drive Without a Secondary Air Pump?.Other Components of a Secondary Air Injection System.

What Is a Secondary Air Injection Pump?.

2001 silverado secondary air monitor