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ECM Power Source Circuit: Procedure

  1. INSPECT ECM (+B, +B1 VOLTAGE) 
    Fig 1: Identifying E3 And E6 Terminal Connectors
    GTY144877Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Turn the ignition switch to ON.
    2. Measure the voltage of the ECM connectors.

      Standard Voltage

      Tester Connection Specified Condition
      E6-6 (+B) - E3-7 (E1) 11 to 14 V
      E6-5 (+B1) - E3-7 (E1) 11 to 14 V

    NG → See step   2 

    OK → PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE 

  2. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    Fig 2: Checking Wire Harness (ECM - Body Ground)
    GTY144830Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the E3 ECM connector.
    2. Measure the resistance of the wire harness side connector.

      Standard Resistance

      Tester Connection Specified Condition
      E3-7 (E1) - Body ground Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  3. INSPECT ECM (IGSW VOLTAGE) 
    Fig 3: Checking ECM (IGSW Voltage)
    GTY126169Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Turn the ignition switch to ON.
    2. Measure the voltage of the ECM connectors.

      Standard Voltage

      Tester Connection Specified Condition
      E6-17 (IGSW) - E3-7 (E1) 11 to 14 V
      RESULT

      Result Proceed to
      NG A
      OK B

    B → See step   7 

    A: Go to next step 

  4. INSPECT FUSE (IGN) 
    Fig 4: Inspecting IGN Fuse
    GTY140273Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the IGN fuse from the engine room No. 2 relay block.
    2. Measure the resistance of the IGN fuse.

      Standard resistance

      Below 1 Ω

    NG → CHECK FOR SHORT IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE 

    OK: Go to next step 

  5. INSPECT IG2 RELAY 
    Fig 5: Inspecting IG2 Relay
    GTY126004Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the IG2 relay from the engine room No. 1 relay block.
    2. Measure the resistance of the IG2 relay.

      Standard Resistance

      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)

    NG → REPLACE IG2 RELAY 

    OK: Go to next step 

  6. INSPECT IGNITION SWITCH 
    Fig 6: Identifying Ignition Switch Connector Terminals
    GTY134898Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the I18 ignition switch connector.
    2. Measure the resistance of the ignition switch.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      6 (IG2) - 7 (AM2) LOCK 10 kΩ or higher
      6 (IG2) - 7 (AM2) ON Below 1 Ω

    NG → REPAIR OR REPLACE IGNITION SWITCH 

    OK: Go to next step 

  7. INSPECT ECM (MREL VOLTAGE) 
    Fig 7: Checking ECM (MREL Voltage)
    GTY144878Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Turn the ignition switch to ON.
    2. Measure the voltage of the ECM connectors.

      Standard Voltage

      Tester Connection Specified Condition
      E6-13 (MREL) - E3-7 (E1) 11 to 14 V

    NG → See step   11 

    OK: Go to next step 

  8. INSPECT FUSE (EFI) 
    Fig 8: Identifying EFI Fuse
    GTY129143Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the EFI fuse from the engine room No. 1 relay block and junction block.
    2. Measure the resistance of the EFI fuse.

      Standard Resistance

      Below 1 Ω

    NG → CHECK FOR SHORT IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE 

    OK: Go to next step 

  9. INSPECT EFI RELAY 
    Fig 9: Inspecting EFI Relay
    GTY126004Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the EFI relay from the engine room No. 2 relay block.
    2. Measure the resistance of the EFI relay.

      Standard Resistance

      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)

    NG → REPLACE EFI RELAY 

    OK: Go to next step 

  10. CHECK HARNESS AND CONNECTOR (EFI RELAY - ECM AND BODY GROUND) 
    Fig 10: Disconnecting E6 ECM Connector Terminals
    GTY132635Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Check the wire harness between the EFI relay and ECM.
      1. Remove the EFI relay from the engine room No. 2 relay block.
      2. Disconnect the E6 ECM connector.
      3. Measure the resistance of the wire harness side connectors.

        Standard Resistance

        Tester Connection Specified Condition
        Relay block EFI relay terminal 2 - E6-13 (MREL) Below 1 Ω
        Relay block EFI relay terminal 2 or E6-13 (MREL) - Body ground 10 kΩ or higher
    2. Check the wire harness between the EFI relay and body ground.
      1. Remove the EFI relay from the engine room No. 2 relay block.
      2. Measure the resistance of the wire harness side connectors.

        Standard Resistance

        Tester Connection Specified Condition
        Relay block EFI relay terminal 1 - Body ground Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → REPAIR OR REPLACE HARNESS OR CONNECTOR (TERMINAL +B OF ECM - POSITIVE (+) BATTERY TERMINAL) 

  11. REPLACE ECM. Refer to  REMOVAL 
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