2008 Lexus SC 430FACTORY OEM SERVICE PROCEDURE

Inspection Procedure

  1. CHECK MIL 
    1. Check that the MIL lights up when turning the ignition switch ON.

    OK: 

    MIL lights up 

    OK: SYSTEM OK 

    NG: Go to next step 

  2. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM 
    1. Connect the Techstream to the DLC3.
    2. Turn the ignition switch ON and tester ON.
    3. Check the communication between the Techstream and ECM.

    Result 

    RESULT CHART

    Condition Proceed to
    Communication is not possible A
    Communication is possible B

    B:  GO TO MIL CIRCUIT 

    A: Go to next step 

  3. CHECK ECM (VC VOLTAGE) 
    1. Turn the ignition switch ON.
    2. Measure the voltage of the ECM connector.

    Result: 

    Voltage is not 5 V 

    Fig 1: Checking ECM (VC Voltage)
    G05291546Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. CHECK MIL (THROTTLE POSITION SENSOR) 
    1. Disconnect the T26 throttle body connector.
    2. Turn the ignition switch ON.
    3. Check the MIL.

    Result 

    RESULT CHART

    Condition Proceed to
    MIL does not illuminate A
    MIL Illuminates B

    B: REPLACE THROTTLE BODY ASSEMBLY 

    A: Go to next step 

  5. CHECK MIL (CANISTER PUMP MODULE) 
    1. Disconnect the C12 canister pump module connector.
    2. Turn the ignition switch ON.
    3. Check the MIL.

    Result 

    RESULT CHART

    Condition Proceed to
    MIL does not Illuminate A
    MIL Illuminates B

    B: REPLACE CANISTER 

    A: Go to next step 

  6. CHECK WIRE HARNESS (ECM - BODY GROUND) 
    1. Disconnect the T26 throttle body connector.
    2. Disconnect the C12 canister pump module connector.
    3. Disconnect the E2 ECM connector.
    4. Measure the resistance of the wire harness connector.

    Standard resistance 

    TESTER CONNECTION SPECIFIED CONDITION CHART

    Tester Connection Specified Condition
    E2-29 (VC) - Body ground 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    Fig 2: Disconnecting E2 ECM Connector
    G05291547Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE ECM 

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

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.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.