2007 Lexus SC 430FACTORY OEM SERVICE PROCEDURE

On-Vehicle Inspection

NOTE: In this information, the terms "Cold" and "Hot" refer to the temperature of the coils.
  • "Cold" means approximately -10 to 50°C (14 to 122°F).
  • "Hot" means approximately 50 to 100°C (122 to 212°F).
  1. PERFORM SPARK TEST 
    1. Check for DTCs.
      NOTE: If a DTC is present, perform troubleshooting procedures for that DTC.
    2. Check if sparks occur.
      1. Remove the ignition coil.
      2. Remove the spark plug.
      3. Install the spark plug to the ignition coil and connect the ignition coil connector.
      4. Disconnect the 8 injector connectors.
      5. Ground the spark plug.
      6. Visually check that sparks occur while the engine is being cranked.
        NOTE:
        • Be sure to ground the spark plug when checking it.
        • If the ignition coil has been struck or dropped, replace it.
        • Do not crank the engine for more than 2 seconds.

        If sparks occur, skip the spark test flowchart. If sparks do not occur, proceed to the spark test flowchart.

    3. Spark test flowchart.
      1. Check that the wire harness side connector of the ignition coil with igniter is securely connected.

        Result 

        RESULT REFERENCE

        Result Proceed to
        NG Connect securely
        OK Go to next step
      2. Perform a spark test on each ignition coil with igniter.
        1. Replace the ignition coil with igniter with a normal one.
        2. Perform the spark test again.

          Result 

          RESULT REFERENCE

          Result Proceed to
          OK Replace ignition coil with igniter
          NG Go to next step
      3. Check the power supply to the ignition coil with igniter.
        1. Turn the ignition switch ON.
        2. Check that there is battery voltage at the ignition coil positive (+) terminal.

          Result 

          RESULT REFERENCE

          Result Proceed to
          NG Check wiring between ignition switch and ignition coil with igniter
          OK Go to next step
      4. Check the resistance of the camshaft position sensor.

        Standard resistance 

        RESISTANCE REFERENCE

        Temperature Specified Condition
        Cold 835 to 1,400 Ω
        Hot 1,060 to 1,645 Ω

        Result 

        RESULT REFERENCE

        Result Proceed to
        NG Replace camshaft position sensor
        OK Go to next step
      5. Check the resistance of the crankshaft position sensor.

        Standard resistance 

        RESISTANCE REFERENCE

        Temperature Specified Condition
        Cold 835 to 1,400 Ω
        Hot 1,060 to 1,645 Ω

        Result 

        RESULT REFERENCE

        Result Proceed to
        NG Replace crankshaft position sensor
        OK Go to next step
      6. Check the IGT signal from the ECM.

        Result 

        RESULT REFERENCE

        Result Proceed to
        NG Check ECM (see DESCRIPTION )
        OK Repair wiring between ignition coil and ECM
    4. Using a 16 mm plug wrench, install the spark plug.

      Torque: 18 N*m (183 kgf*cm, 13 ft.*lbf) 

    5. Install the ignition coil with the bolt.
  2. CHECK SPARK PLUG 
    NOTE:
    • Do not use a wire brush for cleaning.
    • Do not attempt to adjust the electrode gap of a used spark plug.
    1. Check the electrode.
      1. Using a megohmmeter, measure the insulation resistance.

        Insulation resistance: 

        10 MΩ or more 

        HINT:

        If a megohmmeter is not available, perform the following simple inspection instead.

        Fig 1: Checking Electrode
        G05289420Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Alternative inspection method:
      1. Quickly accelerate the engine to 4,000 rpm 5 times.
      2. Remove the spark plug.
      3. Visually check the spark plug.

        If the electrode is dry, the spark plug is functioning properly. If the electrode is damp, proceed to the next step.

        Fig 2: Identifying Spark Plug Condition
        G05289421Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Check the spark plug for any damage on its threads and insulator.

      If there is damage, replace the spark plug. If not, reinstall the spark plug.

      SPARK PLUG SPECIFICATION

      Manufacturer Product
      DENSO SK20R11
      NGK IFR6A11
    4. Check the spark plug electrode gap.

      Maximum electrode gap for used spark plug: 

      1.3 mm (0.051 in.) 

      If the gap is greater than the maximum, replace the spark plug. 

      Electrode gap for new spark plug: 

      1.0 to 1.1 mm (0.039 to 0.043 in.) 

      NOTE: When adjusting the gap of a new spark plug, bend only the base of the ground electrode. Do not touch the tip. Never attempt to adjust the gap of a used plug.
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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