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.
Function And Operation Principle
Variable Intake manifold Solenoid (VIS) valves are installed on surge tank (VIS Valve #1) and intake manifold (VIS Valve #2). These VIS valve #1 and #2 control vacuum modulators which activate valves in surge tank and intake manifold. These valves are opened or closed by PCM according to engine condition. Refer to ENGINE CONDITION .
| Engine Condition | VIS Valve #1 (Surge Tank) | VIS Valve #2 (In-manifold) | Operation |
|---|---|---|---|
| Low Speed | Closed | Closed | Increasing engine performance in low engine speed by reducing intake interference among cylinders |
| Medium Speed | Open | Open or closed | Increasing intake efficiency |
| High Speed | Open | Open | Minimizing intake resistance by shortening intake manifold length and increasing area of air entrance |
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.