LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2010 >> Matrix S, AWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control (SFI) System (2AZ-FE) (Diagnostic Codes (DTC P0451 - DTC P2A00) & Symptom Tests) >> SFI System >> Circuit Test >> ECM Power Source Circuit >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

ECM Power Source Circuit: Procedure

  1. INSPECT INTEGRATION NO. 1 RELAY (POWER SOURCE) 
    Fig 1: Identifying Engine Room Relay Block Connector Terminal
    GTY181950Courtesy 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: Identifying Engine Room Relay Block
    GTY230594Courtesy 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 → REPLACE FUSE (EFI MAIN, IG2 OR EFI NO. 1 FUSE) 

    OK: Go to next step 

  3. INSPECT INTEGRATION NO. 1 RELAY (EFI MAIN RELAY AND IG2 RELAY) 
    Fig 3: Identifying EFI Main Relay Connector Terminals
    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 absent 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 absent 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 Connector And Integration Relay Connector
    GTY213786Courtesy 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
      A37-44 (MREL) - 1B-2 Always Below 1 Ω
      A37-2 (+B) - 1B-4 Always Below 1 Ω
      A37-1 (+B2) - 1B-4 Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      A37-44 (MREL) - Body ground Always 10 kΩ or higher
      A37-2 (+B) - Body ground Always 10 kΩ or higher
      A37-1 (+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 (INTEGRATION RELAY - ECM) 

    OK: Go to next step 

  5. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    Fig 5: Identifying B29 ECM Connector Terminals
    GTY237745Courtesy 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
      B29-104 (E1) - Body ground Always Below 1 Ω
    3. Reconnect the ECM connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND) 

    OK: Go to next step 

  6. INSPECT ECM (IGSW TERMINAL VOLTAGE) 
    Fig 6: Identifying ECM Connector Terminal
    GTY235784Courtesy 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 Condition Specified Condition
      A37-28 (IGSW) - B29-104 (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) 
    1. Remove the IGN fuse from the driver side junction block.
      Fig 7: Identifying IGN Fuse
      GTY215238Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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 → REPLACE FUSE (IGN FUSE) 

    OK: Go to next step 

  8. CHECK HARNESS AND CONNECTOR (ECM - INTEGRATION RELAY) 
    Fig 8: Identifying ECM Connector And Integration Relay Connector
    GTY224803Courtesy 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
      A37-28 (IGSW) - 1A-4 Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      A37-28 (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 (ECM - INTEGRATION RELAY) 

    OK: Go to next step 

  9. INSPECT FUSE (IG2 NO. 2 FUSE) 
    Fig 9: Identifying Engine Room Relay Block
    GTY173650Courtesy 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 → REPLACE FUSE (IG2 NO. 2 FUSE) 

    OK: Go to next step 

  10. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - IGNITION SWITCH) 
    Fig 10: Identifying Engine Room Relay Block
    GTY215070Courtesy 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 - E5-6 (IG2) Always Below 1 Ω
      1A-3 - Body ground Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      E5-6 (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 (INTEGRATION RELAY - ECM) 

    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  COMPONENTS 
  13. REPLACE ECM. Refer to  COMPONENTS 
  14. REPLACE IGNITION SWITCH. Refer to  COMPONENTS 
scientia non olet · About LEMON Manuals