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Home >> Toyota >> 2005 >> Sequoia SR5, RWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine - Diagnostics >> Circuit Inspection >> ECM Power Source Circuit >> Inspection Procedure
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Inspection Procedure

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

    PREPARATION: 

    Turn the ignition switch ON.

    CHECK: 

    Measure the voltage between terminals +B and E1 of the ECM connectors.

    OK: 

    Standard: 9 to 14 V 

    Fig 1: Identifying ECM Connectors Terminals
    G03058482Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. OK: Proceed to next circuit inspection shown in the  PROBLEM SYMPTOMS TABLES 
    2. NG: Go to next step 
  2. Check for open in harness and connector between terminal E1 of ECM and body ground (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
    1. NG: Repair or replace harness or connector. 
    2. OK: Go to next step 
  3. Check voltage between terminal IGSW of ECM connector and body ground. 

    PREPARATION: 

    Turn the ignition switch ON.

    CHECK: 

    Measure the voltage between terminal IGSW of the ECM connector and body ground.

    OK: 

    Fig 2: Identifying IGSW Of ECM Connector Terminals
    G03058483Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Standard: 9 to 14 V 

    1. OK: Go to step   6 . 
    2. NG: Go to next step 
  4. Check IGN1 fuse. 

    PREPARATION: 

    Remove the IGN1 fuse from the instrument panel J/B.

    CHECK: 

    Check the resistance of the IGN1 fuse.

    OK: 

    Below 1 Ω 

    Fig 3: Identifying IGN1 Fuse Location
    G03058484Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Check for short in all harness and components connected to IGN1 fuse. 
    2. OK: Go to next step 
  5. Check ignition switch (See  INSPECTION  ). 

    PREPARATION: 

    1. Remove the lower finish panel.
    2. Disconnect the ignition switch connector.

    CHECK: 

    Check resistance between terminals.

    OK: 

    Fig 4: Identifying Ignition Switch Connector Terminals
    G03058485Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Standard: 

    SWITCH POSITION AND SPECIFIED CONDITION

    Switch Position Terminal Condition Specified Condition
    LOCK Always 10 kΩ or more
    ACC 1 - 3 Below 1 Ω
    ON 1 - 2 - 3 Below 1 Ω
    ON 5 - 6 Below 1 Ω
    START 1 - 2 Below 1 Ω
    START 4 - 5 - 6 Below 1 Ω
    1. NG: Replace ignition switch. 
    2. OK: Check and repair harness and connector between IGN fuse and ECM. 
  6. Check voltage between terminal MREL of ECM connector and body ground. 

    PREPARATION: 

    Turn the ignition switch ON.

    CHECK: 

    Measure the voltage between terminal MREL of the ECM connector and body ground.

    OK: 

    Standard: 9 to 14 V 

    Fig 5: Identifying MREL Of ECM Connector Terminals
    G03058486Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Replace ECM (See  ENGINE CONTROL MODULE (ECM)  ). 
    2. OK: Go to next step 
  7. Check EFI No. 1 fuse of engine room J/B. 

    PREPARATION: 

    Remove the EFI No. 1 fuse from the engine room J/B.

    CHECK: 

    Check resistance of EFI No. 1 fuse.

    OK: 

    Below 1 Ω 

    Fig 6: Identifying EFI Fuse Location
    G03058487Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Check for short in all harness and components connected to EFI No. 1 fuse. 
    2. OK: Go to next step 
  8. Check EFI relay. 

    PREPARATION: 

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

    CHECK: 

    Inspect the EFI relay.

    OK: 

    Standard: 

    SYMBOLS AND SPECIFIED CONDITION

    Terminal No. Condition Specified Condition
    3 - 5 Always 10 kΩ or higher
    3 - 5 Apply B+ between terminals 1 and 2 Below 1 Ω
    Fig 7: Inspecting EFI Relay
    G03058488Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Replace EFI relay. 
    2. OK: Go to next step 
  9. Check for open and short in harness and connector between terminal MREL of ECM and body ground. 

    PREPARATION: 

    Disconnect the E4 ECM connector.

    CHECK: 

    Measure the resistance between the wire harness side connector and body ground.

    OK: 

    Standard: 

    TESTER CONNECTION SPECIFIED CONDITION

    Tester Connection Specified Condition
    MREL (E4-8) - Body ground Below 1 Ω
    Fig 8: Identifying E4 ECM Connector Terminals
    G03058489Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Repair or replace harness or connector. 
    2. OK:  CHECK FOR INTERMITTENT PROBLEMS  
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