Pulsair Valve: Description and Operation

SYSTEM PURPOSE

The Pulsed Secondary Air Injection (PAIR) System is designed to send secondary air to the exhaust manifold to promote afterburning of the exhaust gases, reducing CO and HC. The exhaust pressure in the manifold pulsates in response to the opening and closing of the exhaust valves and decreases periodically below atmospheric pressure creating a vacuum effect.

Pulsed Secondary Air Injection (PAIR/AIV) Input/Output Signals:

CIRCUIT OPERATION
When the ECM senses the proper conditions suitable for PAIR operation, via the water temperature sensor, idle switch and crank angle sensor it supplies the ground circuit to the PAIRC solenoid allowing the system to operate.

Fig. 6 AIV/PAIR Valve:

The vacuum being transmitted to the PAIR Valve acts upon a diaphragm opening the valve port allowing the system to operate. The exhaust flow then draws filtered air into the the manifold through the piping and PAIR Valve promoting afterburning of the unburned exhaust gasses. A set of reed valves are mounted in the PAIR Valve to prevent exhaust gas from being sent back into the unit when the exhaust pressure exceeds atmospheric pressure.

Vacuum Control Solenoid:

PULSED SECONDARY AIR INJECTION (PAIRC) CONTROL SOLENOID
The ECM supplies the ground circuit to the PAIRC solenoid. When activated, it redirects vacuum from the source and vent ports to the source and valve ports, applying vacuum to the PAIR.

PAIR/AIV Solenoid Operation:

PAIR OPERATION CHART