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Home >> Toyota >> 2004 >> ECHO 4D Sedan, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Diagnostics >> DTC Tests >> ECM Power Source Circuit >> Inspection Procedure
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Inspection Procedure

  1. Check voltage between terminals +B and E1 of ECM connectors. 

    PREPARATION: 

    Turn the ignition switch ON.

    CHECK: 

    Measure the voltage between the specified terminals of the E4 and E7 ECM connectors.

    OK: 

    CONNECTION SPECIFIED CONDITION

    Tester Connection Specified Condition
    +B (E4-1) - E1 (E7-7) 9 to 14 V
    Fig 1: Checking Voltage Between Terminals +B And E1 Of ECM Connectors
    G02905381Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Proceed to next circuit inspection shown on problem symptoms table (See  PROBLEM SYMPTOMS TABLE  ). 

    NG: Go to next step. 

  2. Check for open in harness and connector between terminal E1 of ECM and body ground. 

    PREPARATION: 

    Disconnect the E7 ECM connector.

    CHECK: 

    Measure the resistance between the wire harness side connectors.

    OK: 

    Standard (Check for open): 

    SPECIFIED CONDITION

    Tester Connection Specified Condition
    E1 (E7-7) - Body ground Below 1 Ω
    Fig 2: Checking Open In Harness And Connector Between Terminal E1 Of ECM And Body Ground
    G02905382Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Repair or replace harness or connector. 

    OK: Go to next step. 

  3. Check ignition switch. 

    PREPARATION: 

    Disconnect the I10 ignition switch connector.

    CHECK: 

    Measure the resistance between the connector terminals shown in SPECIFIED CONDITION  .

    OK: 

    SPECIFIED CONDITION

    Switch Position Tester Connection Specified Condition
    LOCK All Terminals 10 kΩ or higher
    ACC 1-3 Below 1 Ω
    ON 1-2, 1-3, 2-3, 5-6 Below 1 Ω
    START 4-5, 4-6, 5-6, 1-2 Below 1 Ω
    Fig 3: Check Ignition Switch
    G02905383Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Replace ignition switch. 

    OK: Go to next step. 

  4. Check EFI fuse. 

    PREPARATION: 

    Remove the EFI fuse from the engine room R/B.

    CHECK: 

    Check for continuity in the EFI fuse.

    Standard: Continuity 

    Fig 4: Checking EFI Fuse
    G02905384Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Check for short in all harness and components connected to EFI fuse. 

    OK: Go to next step. 

  5. Check EFI relay (Marking: EFI). 

    PREPARATION: 

    Remove the EFI relay from the engine room R/B.

    CHECK: 

    Inspect the EFI relay.

    OK: 

    Fig 5: Checking EFI Relay
    G02905385Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 6: Specified Condition Table
    G02905386Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Replace EFI relay. 

    OK: Go to next step. 

  6. Check for open and short in harness and connector between EFI relay and ECM, EFI relay and body ground. 

    Check the harness and connector between the EFI relay terminal of R/B and ECM connector.

    PREPARATION: 

    1. Remove the EFI relay from the engine room R/B. 
    2. Disconnect the E4 ECM connector. 

    CHECK: 

    Measure the resistance between the wire harness side connectors.

    Fig 7: Removing EFI Relay From Engine Room R/B
    G02905387Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    Standard (Check for open): 

    SPECIFIED CONDITION

    Tester Connection Specified Condition
    EFI relay terminal 3 of R/B - +B (E4-1) Below 1 Ω.

    Standard (Check for short): 

    SPECIFIED CONDITION

    Tester Connection Specified Condition
    EFI relay terminal 3 of R/B or +B (E4-1) - Body ground 10 kΩ or higher

    Check the harness and connector between the EFI relay terminal of R/B and body ground.

    PREPARATION: 

    Remove the EFI relay from the engine room R/B.

    Fig 8: Measuring Resistance Between Wire Harness Side Connectors
    G02905388Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    CHECK: 

    Check for continuity between the wire harness side connector and body ground.

    OK: 

    SPECIFIED CONDITION

    Tester Connection Specified Condition
    EFI relay terminal 2 of R/B - Body ground Below 1 Ω.

    NG: Repair or replace harness or connector. 

    OK: Go to next step. 

  7. Check AM2 fuse. 

    PREPARATION: 

    Remove the AM2 fuse from the engine room R/B.

    CHECK: 

    Check for continuity in the AM2 fuse.

    Standard: Continuity 

    Fig 9: Removing AM2 Fuse From Engine Room R/B
    G02905389Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Check for short in all harnesses and components connected to AM2 fuse. 

    OK: Go to next step. 

  8. Check for open and short in harness and connector between EFI relay and EFI fuse. 

    PREPARATION: 

    1. Remove the EFI relay from the engine room R/B. 
    2. Remove the EFI fuse from the engine room R/B. 

    CHECK: 

    Measure the resistance between the wire harness side connectors.

    OK: 

    Standard (Check for open): 

    SPECIFIED CONDITION

    Tester Connection Specified Condition
    EFI relay terminal 5 of R/B - EFI fuse terminal 2 of R/B Below 1 Ω
    Fig 10: Removing EFI Relay From Engine Room R/B
    G02905390Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Standard (Check for short): 

    SPECIFIED CONDITION

    Tester Connection Specified Condition
    EFI relay terminal 5 of R/B or EFI fuse terminal 2 of R/B - Body ground 10 kΩ or higher
    Fig 11: Removing EFI Fuse From Engine Room R/B
    G02905391Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Repair or replace harness or connector. 

    OK: Go to next step. 

  9. Check for open and short in harness and connector between EFI relay and ignition switch. 

    PREPARATION: 

    1. Remove the EFI relay from the engine room R/B. 
    2. Disconnect the I10 ignition switch connector. 

    CHECK: 

    Measure the resistance between the wire harness side connectors.

    OK: 

    Standard (Check for open): 

    SPECIFIED CONDITION

    Symbols (Terminal No.) Specified condition
    IG2 (I10-6) - EFI relay terminal 1 of R/B Below 1 Ω
    Fig 12: Disconnecting I10 Ignition Switch Connector
    G02905392Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Standard (Check for short): 

    SPECIFIED CONDITION

    Symbols (Terminal No.) Specified condition
    IG2 (I10-6) or EFI relay terminal 1 of R/B - Body ground 10 kΩ or higher
    Fig 13: Removing EFI Relay From Engine Room R/B
    G02905393Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Repair or replace harness or connector. 

    OK: Go to next step. 

  10. Check for open and short in harness and connector between ignition switch and AM2 fuse. 

    PREPARATION: 

    1. Disconnect the I10 ignition switch connector. 
    2. Remove the AM2 fuse from the engine room R/B. 

    CHECK: 

    Measure the resistance between the wire harness side connectors.

    OK: 

    Standard (Check for open): 

    SPECIFIED CONDITION

    Symbols (Terminal No.) Specified condition
    AM2 (I10-5) - AM2 fuse terminal 2 of R/B Below 1 Ω
    Fig 14: Disconnecting I10 Ignition Switch Connector
    G02905394Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Standard (Check for short): 

    SPECIFIED CONDITION

    Symbols (Terminal No.) Specified condition
    AM2 (I10-5) - AM2 fuse terminal 2 of R/B - Body ground 10 kΩ or higher
    Fig 15: Removing AM2 Fuse From Engine Room R/B
    G02905395Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Repair or replace harness or connector. 

    OK: Go to next step. 

    Check and repair harness and connector between AM2 fuse and battery positive terminal, EFI fuse and buttery positive terminal.

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