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ECM Power Source Circuit: Procedure

  1. INSPECT INTEGRATION NO. 1 RELAY (POWER SOURCE) 
    Fig 1: Inspecting Integration No. 1 Relay (Power Source)
    GTY162054Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the integration relay from the engine room relay block.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      1E-1 - Body ground Always 11 to 14 V
    3. Reinstall the integration relay.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY - BATTERY) 

    OK: Go to next step 

  2. INSPECT FUSES (EFI MAIN, IG2, AND EFI NO. 1 FUSES) 
    Fig 2: Inspecting Fuses (EFI Main, IG2, And EFI No. 1 Fuses)
    GTY161094Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the EFI MAIN fuse, IG2 fuse and EFI NO. 1 fuse from the engine room relay block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      EFI MAIN fuse Always Below 1 Ω
      IG2 fuse
      EFI NO. 1 fuse
    3. Reinstall the fuses.

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

    OK: Go to next step 

  3. INSPECT INTEGRATION NO. 1 RELAY (EFI MAIN RELAY AND IG2 RELAY) 
    Fig 3: Inspecting Integration No. 1 Relay (EFI Main Relay And IG2 Relay)
    GTY165370Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the integration relay from the engine room relay block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1E-1 - 1B-4 When battery voltage not applied 10 kΩ or higher
      When battery voltage applied to terminals 1B-2 and 1B-3 Below 1 Ω
      1E-1 - 1A-4 When battery voltage not applied 10 kΩ or higher
      When battery voltage applied to terminals 1A-2 and 1A-3 Below 1 Ω
    3. Reinstall the integration relay.

    NG → See step   12 

    OK: Go to next step 

  4. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM) 
    Fig 4: Identifying ECM And Integration Relay Connector Terminals
    GTY162589Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the integration relay from the engine room relay block.
    2. Disconnect the ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for open)

      Tester Connection Condition Specified Condition
      A36-44 (MREL) - 1B-2 Always Below 1 Ω
      A36-2 (+B) - 1B-4 Always Below 1 Ω
      A36-1 (+B2) - 1B-4 Always Below 1 Ω

      Standard Resistance (Check for short)

      Tester Connection Condition Specified Condition
      A36-44 (MREL) - Body ground Always 10 kΩ or higher
      A36-2 (+B) - Body ground Always 10 kΩ or higher
      A36-1 (+B2) - Body ground Always 10 kΩ or higher
    4. Reinstall the integration relay.
    5. Reconnect the ECM connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  5. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    Fig 5: Identifying B33 ECM Connector
    GTY161012Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the ECM connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for open)

      Tester Connection Condition Specified Condition
      B33-104 (E1) - Body ground Always Below 1 Ω
    3. Reconnect the ECM connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  6. INSPECT ECM (IGSW TERMINAL VOLTAGE) 
    Fig 6: Inspecting ECM (IGSW Terminal Voltage)
    GTY161602Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the ECM connectors.
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      A36-28 (IGSW) - B33-104 (E1) Ignition switch ON 11 to 14 V
    4. Reconnect the ECM connectors.

    NG → See step   7 

    OK → See step   13 

  7. INSPECT FUSE (IGN FUSE) 
    Fig 7: Inspecting Fuse (IGN Fuse)
    GTY162423Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the IGN fuse from the main body ECU.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      IGN fuse Always Below 1 Ω
    3. Reinstall the IGN fuse.

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

    OK: Go to next step 

  8. CHECK HARNESS AND CONNECTOR (ECM - INTEGRATION RELAY) 
    Fig 8: Identifying ECM And Integration Relay Connector
    GTY160926Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the integration relay from the engine room relay block.
    2. Disconnect the ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for open)

      Tester Connection Condition Specified Condition
      A36-28 (IGSW) - 1A-4 Always Below 1 Ω

      Standard Resistance (Check for short)

      Tester Connection Condition Specified Condition
      A36-28 (IGSW) - Body ground Always 10 kΩ or higher
    4. Reinstall the integration relay.
    5. Reconnect the ECM connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  9. INSPECT FUSE (IG2 NO. 2 FUSE) 
    Fig 9: Identifying IG2 NO. 2 Fuse Location
    GTY344327Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the IG2 NO. 2 fuse from the engine room relay block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      IG2 NO. 2 fuse Always Below 1 Ω
    3. Reinstall the fuse.

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

    OK: Go to next step 

  10. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - IGNITION SWITCH) 
    Fig 10: Identifying Ignition Switch Connector Terminals
    GTY163731Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the integration relay from the engine room relay block.
    2. Disconnect the ignition switch connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for open)

      Tester Connection Condition Specified Condition
      1A-2 - C5-6 (IG2) Always Below 1 Ω
      1A-3 - Body ground Always Below 1 Ω

      Standard Resistance (Check for short)

      Tester Connection Condition Specified Condition
      C5-6 (IG2) - Body ground Always 10 kΩ or higher
    4. Reinstall the integration relay.
    5. Reconnect the ignition switch connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  11. INSPECT IGNITION SWITCH 
    Fig 11: Inspecting Ignition Switch
    GTY165527Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the ignition switch.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      All Terminals LOCK 10 kΩ or higher
      2 (AM1) - 3 (ACC) ACC Below 1 Ω
      2 (AM1) - 3 (ACC) - 4 (IG1) ON
      7 (AM2) - 6 (IG2)
      2 (AM1) - 4 (IG1) - 1 (ST1) START
      7 (AM2) - 6 (IG2) - 8 (ST2)
    3. Reinstall the ignition switch.

    NG → See step   14 

    OK → REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION SWITCH - BATTERY) 

  12. REPLACE INTEGRATION NO. 1 RELAY. Refer to  REMOVAL  .
  13. REPLACE ECM. Refer to  REMOVAL  .
  14. REPLACE IGNITION SWITCH. Refer to  REMOVAL  .
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