2006 Toyota Sienna CEFACTORY OEM SERVICE PROCEDURE

Inspection Procedure

  1. CHECK FUSE (IGN FUSE) 
    1. Remove the IGN fuse from the driver side J/B.
    2. Measure the IGN fuse resistance.

      Standard resistance: Below 1 Ω 

    3. Reinstall the IGN fuse.
      Fig 1: Checking Fuse (IGN Fuse)
      G04493791Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE 

    OK: GO TO NEXT STEP 

  2. CHECK FUSE (EFI NO. 1 FUSE) 
    1. Remove the EFI No. 1 fuse from the engine room J/B.
    2. Measure the EFI No. 1 fuse resistance.

      Standard resistance: Below 1 Ω 

    3. Reinstall the EFI No. 1 fuse.
      Fig 2: Checking Fuse (EFI No. 1 Fuse)
      G04493792Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE 

    OK: GO TO NEXT STEP 

  3. INSPECT ECM (+B VOLTAGE) 
    1. Turn the ignition switch ON.
    2. Measure the voltage of the ECM connectors.

      Standard voltage 

      ECM (+B VOLTAGE)

      Tester Connection Specified Condition
      E4-1 (+B) - E6-1 (E1) 9 to 14 V
      Fig 3: Inspecting ECM (+B Voltage)
      G04493793Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE  

    NG: GO TO NEXT STEP 

  4. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    1. Disconnect the E6 ECM connector.
    2. Check the resistance.

      Standard resistance 

      ECM - BODY GROUND

      Tester Connection Specified Condition
      E6-1 (E1) - Body ground Below 1 Ω
      Fig 4: Checking Harness And Connector (ECM - Body Ground)
      G04493794Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Reconnect the ECM connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: GO TO NEXT STEP 

  5. INSPECT ECM (IGSW VOLTAGE) 
    1. Turn the ignition switch ON.
    2. Measure the voltage of the ECM connectors.

      Standard voltage 

      ECM (IGSW VOLTAGE)

      Tester Connection Specified Condition
      E4-9 (IGSW) - E6-1 (E1) 9 to 14 V
      Fig 5: Inspecting ECM (IGSW Voltage)
      G04493795Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to step   7 

    NG: GO TO NEXT STEP 

  6. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY 
    1. Measure the resistance of the switch terminals shown in the chart below.

      Standard resistance 

      IGNITION OR STARTER SWITCH ASSEMBLY

      Switch Terminal No. Specified Condition
      LOCK All terminals 10 kΩ or higher
      ACC 1 - 3 Below 1 Ω
      ON 1 - 2, 1 - 3, 2 - 3, 5 - 6
      START 4 - 5, 4 - 6, 5 - 6, 1 - 2
      Fig 6: Inspecting Ignition Or Starter Switch Assembly
      G04493796Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE IGNITION OR STARTER SWITCH ASSEMBLY 

    OK: CHECK AND REPLACE HARNESS AND CONNECTOR (BATTERY - IGNITION SWITCH, IGNITION SWITCH - ECM) 

  7. INSPECT ECM (MREL VOLTAGE) 
    1. Turn the ignition switch ON.
    2. Measure the voltage of the ECM connectors.

      Standard voltage 

      ECM (MREL VOLTAGE)

      Tester Connection Specified Condition
      E4-8 (MREL) - E6-1 (E1) 9 to 14 V
      Fig 7: Inspecting ECM (MREL Voltage)
      G04493797Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE ECM 

    OK: GO TO NEXT STEP 

  8. INSPECT EFI RELAY 
    1. Remove the EFI relay from the engine room J/B.
    2. Measure the resistance of the EFI relay.

      Standard resistance 

      EFI RELAY

      Tester Connection Specified Condition
      3 - 5 10 kΩ or higher
      3 - 5 Below 1 Ω
      (when battery voltage is applied to terminals 1 and 2)
      Fig 8: Inspecting EFI Relay
      G04493798Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Reinstall the EFI relay.

    NG: REPLACE EFI RELAY 

    OK: GO TO NEXT STEP 

  9. CHECK HARNESS AND CONNECTOR (EFI RELAY- ECM, EFI RELAY - BODY GROUND) 
    1. Check the wire harness between the EFI relay and ECM.
      1. Remove the EFI relay from the engine room J/B.
      2. Disconnect the E4 ECM connector.
      3. Check the resistance.

        Standard resistance 

        EFI RELAY- ECM, EFI RELAY - BODY GROUND (1 OF 2)

        Tester Connection Specified Condition
        J/B EFI relay terminal 1 - E4-8 (MREL) Below 1 Ω
        J/B EFI relay terminal 1 or E4-8 (MREL) - Body ground 10 kΩ or higher
      4. Reinstall the EFI relay.
      5. Reconnect the ECM connector.
    2. Check the wire harness between the EFI relay and body ground.
      1. Remove the EFI relay from the engine room J/B.
      2. Check the resistance.

        Standard resistance 

        EFI RELAY- ECM, EFI RELAY - BODY GROUND (2 OF 2)

        Tester Connection Specified Condition
        J/B EFI relay terminal 2 - Body ground Below 1 Ω
        Fig 9: Checking Harness And Connector (EFI Relay - ECM, EFI Relay - Body Ground)
        G04493799Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      3. Reinstall the EFI relay.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: CHECK AND REPAIR HARNESS AND CONNECTOR (TERMINAL +B OF ECM - BATTERY POSITIVE TERMINAL) 

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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.