2005 Toyota Avalon XLSFACTORY OEM SERVICE PROCEDURE

Inspection Procedure

  1. INSPECT ECM (+B VOLTAGE) 
    1. Turn the ignition switch on (IG).
    2. Measure the voltage between the terminals of the A24 and B47 ECM connectors.
      Fig 1: Measuring Voltage Between Terminals Of A24 And B47 ECM Connectors
      G02976366Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard: 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connections Specified Conditions
      +B (A24-1) - E1 (B47-1) 9 to 14 V
    1. OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS TABLE (SEE  PROBLEM SYMPTOMS TABLE  ) 
    2. NG: Go to next step. 
  2. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    1. Disconnect the B47 ECM connector.
    2. Measure the resistance between the terminal of the ECM connector and body ground.

      Standard (Check for open): 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connections Specified Conditions
      E1 (B47-1) - Body ground Below 1 Ω
    3. Reconnect the ECM connector.
      Fig 2: Measuring Resistance Between Terminal Of ECM Connector And Body Ground
      G02976367Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 
    2. OK: Go to next step. 
  3. INSPECT ECM (IGSW VOLTAGE) 
    1. Turn the ignition switch on (IG).
    2. Measure the voltage between the terminals of the A24 and B47 ECM connectors.

      Standard: 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connections Specified Conditions
      IGSW (A24-9) - E1 (B47-1) 9 to 14 V
      Fig 3: Measuring Voltage Between Terminals Of A24 And B47 ECM Connectors
      G02976368Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. OK: Go to step   6 . 
    2. NG: Go to next step. 
  4. CHECK FUSE (IGN FUSE) 
    1. Remove the IGN fuse from the instrument panel J/B.
    2. Measure the IGN fuse resistance.

      Standard: Below 1 Ω 

    3. Reinstall the IGN fuse.
      Fig 4: Identifying IGN Fuse
      G02976369Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO FUSE, AND REPLACE FUSE 
    2. OK: Go to next step. 
  5. INSPECT IGNITION OR STARTER SWITCH ASSY (SEE  INSPECTION  ) 
    1. NG: REPLACE IGNITION OR STARTER SWITCH ASSY 
    2. OK: CHECK AND REPAIR HARNESS AND CONNECTOR (BATTERY - IGNITION SWITCH, IGNITION SWITCH - ECM) 
  6. INSPECT ECM (MREL VOLTAGE) 
    1. Turn the ignition switch on (IG).
    2. Measure the voltage between the terminals of the A24 and B47 ECM connectors.

      Standard: 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connections Specified Conditions
      MREL (A24-8) - E1 (B47-1) 9 to 14 V
      Fig 5: Measuring Voltage Between Terminals Of A24 And B47 ECM Connectors
      G02976370Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPLACE ECM (SEE  REPLACEMENT  ) 
    2. OK: Go to next step. 
  7. CHECK FUSE (EFI FUSE) 
    1. Remove the EFI No. 1 fuse from the engine room R/B and J/B.
    2. Measure the EFI No. 1 fuse resistance.

      Standard: Below 1 Ω 

    3. Reinstall the EFI No. 1 fuse.
      Fig 6: Locating EFI Fuse
      G02976371Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO FUSE, AND REPLACE FUSE 
    2. OK: Go to next step. 
  8. INSPECT ENGINE ROOM JUNCTION BLOCK ASSY (EFI RELAY) 
    1. Remove the engine room junction block.
    2. Measure the EFI relay resistance.

      Standard: 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connections Specified Conditions
      1D-4 - 1D-6 10 kΩ or higher
      1D-4 - 1D-6 Below 1 Ω (when battery voltage applied to terminals 1H-10 and 1H-2)
    3. Reinstall the engine room junction block.
      Fig 7: Locating Engine Room
      G02976372Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPLACE ENGINE ROOM JUNCTION BLOCK ASSY 
    2. OK: Go to next step. 
  9. CHECK HARNESS AND CONNECTOR (EFI RELAY - ECM, EFI RELAY - BODY GROUND) 
    1. Check the harness and connector between the EFI relay and ECM.
      1. Remove the engine room junction block.
      2. Disconnect the A24 ECM connector.
      3. Measure the resistance between the terminals of the ECM connector and engine room junction block (EFI relay).

        Standard (Check for open): 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connections Specified Conditions
        Engine Room Junction Block (EFI relay) (1H-10) - MREL (A24-8) Below 1 Ω

        Standard (Check for short): 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connections Specified Conditions
        Engine Room Junction Block (EFI relay) (1H-10) or MREL (A24-8) - Body ground 10 kΩ or higher
        Fig 8: Identifying Engine Room Junction Block
        G02976373Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Check the harness and connector between the engine room junction block (EFI relay) and body ground.
      1. Measure the resistance between the terminal of the engine room junction block (EFI relay) and body ground.

        Standard (Check for open): 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connections Specified Conditions
        Engine Room Junction Block (EFI relay) (1H-2) - Body ground Below 1 Ω
        Fig 9: Measuring Resistance Between Terminal
        G02976374Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. Reinstall the engine room junction block.
      3. Reconnect the ECM connector.
    1. OK: REPAIR OR REPLACE HARNESS OR CONNECTOR 
    2. NG: CHECK AND REPAIR HARNESS AND CONNECTOR (TERMINAL +B OF ECM - BATTERY POSITIVE TERMINAL) 
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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