Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
CALIFORNIA Models
Secondary (fresh) air is supplied to the exhaust port on the No. 2 and No. 4 cylinder side by the air suction valve (ASV-I) with cut-off valve. The air injection system is controlled by both coolant temperature sensed by the thermosensor and time governed by the ECM.
When coolant temperature is less than 95°F (35°C), the electronic control module signals the solenoid valve to allow manifold vacuum to open the cut-off valve. This enables the suction valve to operate. The solenoid valve remains open for a period of 123 seconds.
During this time, if a low vacuum condition (such as wide open throttle) should exist, a check valve is used to maintain vacuum at the solenoid and cut-off valve.
At the end of the 123 second period, the control module turns off the solenoid valve signal. Vacuum is no longer supplied to the cut-off valve and air injection is terminated. See Fig 1 .
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.