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.

2006 Lexus SC 430FACTORY OEM SERVICE PROCEDURE

Intake Air Control System: Inspection

INSPECT INTAKE AIR CONTROL VALVE ACTUATOR
1. Attach a vacuum pump to the actuator. Apply a vacuum of 39.9 kPa (300 mmHg, 11.8 in.Hg) and check that the diaphragm's lever moves.
2. Leave the diaphragm as is for 1 minute. Check that the vacuum pump's vacuum reading has not changed.
  If the result is not as specified, replace the actuator or IAC valve.
  
  Fig 1: Inspecting Intake Air Control Valve Actuator
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT VACUUM CONTROL VALVE SET
1. Attach a vacuum pump to the port A. While holding the port B closed, apply a vacuum of 66.7 kPa (500 mmHg, 20 in.Hg) and leave the diaphragm as is for 1 minute. Check that the vacuum pump's vacuum reading has not changed.
  
  Fig 2: Attaching Vacuum Pump To Port A
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check that there is no ventilation when pressure is applied to port B, and that there is ventilation when a vacuum is applied to port B.
  If the result is not as specified, replace the vacuum control valve set.
  
  Fig 3: Checking No Ventilation When Pressure Is Applied To Port B
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT ACIS VSV

Measure the resistance of the VSV.

Standard:

ACIS VSV RESISTANCE

Tester Connection	Specified Condition
1 - 2	33 to 39 ohms at 20°C (68°F)
1 - Body ground 2 - Body ground	10 k ohms or higher

If the result is not as specified, replace the VSV.

Fig 4: Measuring Resistance Of VSV

G02958834

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check operation of the VSV.
1. Check that air flows from port E to the filter.
  If the result is not as specified, replace the VSV.
  
  Fig 5: Checking VSV Operation
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Apply battery positive voltage across the terminals.
3. Check that air flows from port E to port F.
  If the result is not as specified, replace the VSV.
  
  Fig 6: Checking Air Flows From Port E To Port F
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Factory Service Tools

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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.

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