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Inspection Procedure

  1. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM) 
    1. Remove the combination meter assembly, but do not disconnect the connector.
    2. Connect an oscilloscope to terminal F1 -17 (+S) and the body ground.
    3. Shift the transmission gear selector lever to the neutral position.
    4. Jack up the vehicle.
    5. Turn the ignition switch on.
    6. Turn the wheel slowly.
    7. Check the signal waveform according to the condition in the table below.
      WAVEFORM SIGNAL REFERENCE CHART

      Item Condition
      Tester Range 5V/DIV, 20 msec/DIV
      Vehicle Condition Driving at approximately 20 km/h (12 mph)

      OK: The waveform is displayed as shown in the illustration. 

      HINT:

      As the vehicle speed increases, the cycle of the waveform narrows.

    NG: Go to step 2 

    Fig 1: Identifying Combination Meter Assembly Connector Terminals
    G05402882Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : RETURN TO THE ORIGINAL INSPECTION FOR OTHER SYSTEM 

  2. INSPECT COMBINATION METER ASSEMBLY (INPUT VOLTAGE) 
    1. Disconnect the F1 combination meter assembly connector.
    2. Measure the voltage according to the value in the table below.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATIONS

      Tester Connection Switch Condition Specified Condition
      F1-17 (+S) - Body ground Ignition switch on 4.5 to 14 V

      HINT:

      If any of the ECUs specified in the wiring diagram supplied power to the combination meter, the combination meter will output a waveform.

    3. Reconnect the combination meter assembly connector.

    NG:  Go to step  5

    Fig 2: Identifying F1 Combination Meter Assembly Connector Terminals
    G05402883Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  3. INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE) 
    1. Disconnect the A14 brake actuator (skid control ECU) connector or the A15 ABS and traction actuator (skid control ECU) connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      Vehicles with ABS:: 

      STANDARD VOLTAGE SPECIFICATIONS

      Tester Connection Switch Condition Specified Condition
      A14-22 (SP1) - Body ground Ignition switch on 11 to 14 V

      Vehicles with VSC: 

      TESTER CONNECTION AND SPECIFIED CONDITION

      Tester Connection Switch Condition Specified Condition
      A15-11 (SP1) - Body ground Ignition switch on 11 to 14 V
    3. Reconnect the brake actuator (skid control ECU) connector or the ABS and traction actuator (skid control ECU) connector.

    NG:  Go to step  8

    Fig 3: Identifying A14 Brake Actuator (Skid Control ECU) Connector Terminals
    G05402884Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  4. INSPECT COMBINATION METER ASSEMBLY (INPUT WAVEFORM) 
    1. Reconnect the A14 brake actuator (skid control ECU) connector or A15 ABS and traction actuator (skid control ECU) connector.
    2. Remove the combination meter assembly, but do not disconnected the connector.
    3. Connect an oscilloscope to terminal F1-18 (SI) and the body ground.
    4. Shift the transmission gear selector lever to the neutral position.
    5. Jack up the vehicle.
    6. Turn the ignition switch on.
    7. Turn the wheel slowly.
    8. Check the signal waveform according to the condition in the table below.
      WAVEFORM SIGNAL REFERENCE CHART

      Item Condition
      Tester Range 5V/DIV, 20 msec/DIV
      Vehicle Condition Driving at approximately 20 km/h (12 mph)

      OK: The waveform is displayed as shown in the illustration. 

      Fig 4: Identifying Combination Meter Assembly Connector Terminals
      G05402885Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT:

      As the vehicle speed increases, the cycle of the waveform narrows.

      Result 

      RESULT DESCRIPTION

      Result Proceed to
      OK A
      NG (Vehicle with ABS) B
      NG (Vehicle with VSC) C

    B : REPLACE BRAKE ACTUATOR (SKID CONTROL ECU)  (See REMOVAL )

    C : REPLACE ABS AND TRACTION ACTUATOR (SKID CONTROL ECU)  (See REMOVAL )

    A : REPLACE COMBINATION METER ASSEMBLY  (See REMOVAL  )

  5. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - MAIN BODY ECU) 
    1. Disconnect the 4C main body ECU connector.
    2. Disconnect the F1 combination meter assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION AND SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      F1-17 (+S) - 4C-8 Always Below 1 Ω
      F1-17 (+S) or 4C-8 - Body ground Always 10 kΩ or higher
    4. Reconnect the main body ECU connector.
    5. Reconnect the combination meter assembly connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 5: Identifying F1 Combination Meter Assembly Connector Terminals
    G05402886Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  6. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY MALFUNCTIONING ECU) 
    Fig 6: Identifying Combination Meter Assembly Malfunctioning ECU Connectors Terminals
    G05402887Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the F1 combination meter assembly connector.
    2. Disconnect the A21 ECM connector, F12 radio receiver connector or F26 tire pressure warning ECU connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION AND SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      F1-17 (+S) - A21-8 (SPD) Always Below 1 Ω
      F1-17 (+S) - F12-3 (SPD) Always Below 1 Ω
      F1-17 (+S) - F26-2 (SPD) Always Below 1 Ω
      F1-17 (+S) or A21-8 (SPD) - Body ground Always 10 kΩ or higher
      F1-17 (+S) or F12-3 (SPD) - Body ground Always 10 kΩ or higher
      F1-17 (+S) or F26-2 (SPD) - Body ground Always 10 kΩ or higher
    4. Reconnect the combination meter assembly connector.
    5. Reconnect the ECM connector, the radio receiver connector or the tire pressure warning ECU connector.

    NG: Go to step 7 

    OK : REPLACE MALFUNCTIONING ECU 

  7. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - MALFUNCTIONING ECU) 
    1. Disconnect the 4B, 4C or 4D main body ECU connector(s).
      Fig 7: Identifying Main Body ECU - Malfunctioning ECU Connectors Terminals
      G05402888Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the A21 ECM connector, the F12 radio receiver connector or F26 tire pressure warning ECU connector.
    3. Measure the resistance according to the values in the table below.

      Standard resistance 

      TESTER CONNECTION AND SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      A21-8 (SPD) - 4B-26 Always Below 1 Ω
      F12-3 (SPD) - 4D-8 Always Below 1 Ω
      F26-2 (SPD) - 4D-8 Always Below 1 Ω
      A21-8 (SPD) or 4B-26 - Body ground Always 10 kΩ or higher
      F12-3 (SPD) or 4D-8 - Body ground Always 10 kΩ or higher
      F26-2 (SPD) or 4D-8 - Body ground Always 10 kΩ or higher
    4. Reconnect the main body ECU connector.
    5. Reconnect the ECM connector, the radio receiver connector or the tire pressure warning ECU connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK : REPLACE MAIN BODY ECU 

  8. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - SKID CONTROL ECU) 
    1. Disconnect the F1 combination meter assembly connector.
    2. Disconnect the A14 brake actuator (skid control ECU) connector or the A15 ABS and traction actuator (skid control ECU) connector.
    3. Measure the resistance according to the values in the table below.

      Standard resistance 

      Vehicles with ABS: 

      TESTER CONNECTION AND SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      F1-18 (SI) - A14-22 (SP1) Always Below 1 Ω
      F1-18 (SI) or A14-22 (SP1) - Body ground Always 10 kΩ or higher

      Vehicles with VSC: 

      TESTER CONNECTION AND SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      F1-18 (SI) - A15-11 (SP1) Always Below 1 Ω
      F1-18 (SI) or A15-11 (SP1) - Body ground Always 10 kΩ or higher
    4. Reconnect the combination meter assembly connector.
    5. Reconnect the brake actuator (skid control ECU) connector or the ABS and traction actuator (skid control ECU) connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 8: Identifying A14 Brake Actuator (Skid Control ECU) Connector Terminals
    G05402889Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : REPLACE COMBINATION METER ASSEMBLY  (See REMOVAL  )

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