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Home >> Lexus >> 2008 >> ES 350 >> Repair and Diagnosis >> Electrical >> Gauges >> Meter >> Meter / Gauge System >> Speed Signal Circuit >> Inspection Procedure

Inspection Procedure

  1. INSPECT COMBINATION METER ASSEMBLY 
    1. Check the output waveform
      1. Remove the combination meter assembly with connector(s) still connected
      2. Connect the oscilloscope to the terminals E20-12 (+S) and body ground.
      3. Turn the engine switch on (IG).
      4. Turn the wheel slowly.
      5. Check the signal waveform according to the condition(s) in the table below.
        ITEM CONDITION CHART

        Item Condition
        Tool setting 5 V/DIV, 20 ms/DIV
        Vehicle condition Driving at approx 20 km/h (12 mph)

        OK: 

        The waveform is displayed as shown in the illustration. 

        HINT.

        When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

        6. Fig 1: Identifying Combination Meter Assembly Connector
        G05837853Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Go to step 2 

    OK: RETURN TO THE ORIGINAL INSPECTION FOR OTHER SYSTEM 

  2. INSPECT ECU TERMINAL VOLTAGE 
    1. Disconnect the E20 connector.
    2. Measure the voltage according to the value(s) in the table below

      Standard voltage 

      VOLTAGE SPECIFICATION

      Tester Connection Condition Specified Condition
      E20-12 (+S) - Body ground Turn the ignition switch on (IG) 4.5 to 14 V
      Fig 2: Identifying E20 Connector Terminals
      G05837854Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT:

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

    NG:  Go to step  5

    OK: Go to next step 

  3. INSPECT COMBINATION METER ASSEMBLY 
    1. Reconnect the E20 connector.
    2. Disconnect the A36 connector.
    3. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      VOLTAGE SPECIFICATION

      Tester Connection Condition Specified Condition
      A36-12 (SP1) - Body ground Turn the engine switch on (IG) 10 to 14 V
      Fig 3: Identifying E20 And A36 Connector Terminals
      G05837855Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG:  Go to step  18

    OK: Go to next step 

  4. INSPECT SKID CONTROL ECU 
    1. Check the input waveform.
      1. Reconnect the A36 connector.
      2. Remove the combination meter assembly with connector(s) still connected.
      3. Connect the oscilloscope to the terminals E20-14 (SI) and body ground.
      4. Turn the engine switch on (IG)
      5. Turn the wheel slowly.
      6. Check the signal waveform according to the condition(s) in the table below.
        ITEM CONDITION CHART

        Item Condition
        Tool setting 5 V/DIV, 20 ms/DIV
        Vehicle condition Driving at approx 20 km/h (12 mph)
        Fig 4: Identifying E20 Connector Terminals
        G05837856Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

        OK: 

        The waveform is displayed as shown in the illustration. 

        HINT:

        When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

    NG: REPLACE SKID CONTROL ECU 

    OK: REPLACE COMBINATION METER ASSEMBLY 

  5. CHECK HARNESS AND CONNECTOR (COMBINATION METER - NO. 3 JUNCTION BLOCK) 
    1. Disconnect the 3P to 3U No. 3 junction block connector.
      Fig 5: Identifying No. 3 Junction Block Connector Terminals
      G05837857Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      E20-12 (+S) - 3P-6 Always Below 1 Ω
      E20-12 (+S) - Body ground Always 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  6. CHECK HARNESS AND CONNECTOR (NO. 3 JUNCTION BLOCK) 
    1. Inspect for a short in the circuit that connected the No. 3 junction block shown in the wiring diagram.

      HINT:

      If voltage is not present, the circuit (ECU) was possibly the malfunctioning circuit, This is the circuit that will be diagnosed by following the A step that follows.

      1. Disconnect the 3G to 3M and 3A to 3H No. 3 junction block connectors.
        Fig 6: Identifying No. 3 Junction Block Connector Terminals
        G05837858Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. Measure the voltage according to the value(s) in the table below

        Standard voltage 

        VOLTAGE SPECIFICATION

        Tester Connection Condition Specified Condition
        3A-7 - Body ground Turn the engine switch on (IG) 4.5 to 14 V
        3F-5 - Body ground Turn the engine switch on (IG) 4.5 to 14 V
        3H-6 - Body ground Turn the engine switch on (IG) 4.5 to 14 V

        Result 

        RESULT CHART

        Result Proceed to
        Voltage is not present in one circuit A
        Voltage is present in all the circuit. B

    B: REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 3 JUNCTION BLOCK) 

    A: Go to next step 

  7. CHECK HARNESS AND CONNECTOR (NO. 3 JUNCTION BLOCK - NO. 4 JUNCTION BLOCK) 
    1. Disconnect the 4H to 4M No. 4 junction block connector.
      Fig 7: Identifying No. 4 Junction Block Connector Terminals
      G05837859Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      3F-5 - 4M-8 Always Below 1 Ω
      4M-8 - Body ground Always 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  8. CHECK HARNESS AND CONNECTOR (NO. 4 JUNCTION BLOCK) 
    1. Disconnect the 4A to 4G No. 4 junction block connector
      Fig 8: Identifying No. 4 Junction Block Connector Terminals
      G05837860Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below

      Standard voltage 

      VOLTAGE SPECIFICATION

      Tester Connection Condition Specified Condition
      4D-7 - Body ground Turn the engine switch on (IG) 4.5 to 14 V
      4E-7 - Body ground Turn the engine switch on (IG) 4.5 to 14 V
      4G-7 - Body ground Turn the engine switch on (IG) 4.5 to 14 V
      4J-7 - Body ground Turn the engine switch on (IG) 4.5 to 14 V

    B: REPAIR OR REPLACE HARNESS AND CONNECTOR (NO.4 JUNCTION BLOCK) 

    A: Go to next step 

  9. SYSTEM CHECK 
    1. Select the circuit in which is not present voltage in step  8.

      Result 

      RESULT CHART

      Tester Connection System That Uses the Circuit Proceed to
      3A-7 - Body ground Smart Key System A
      3H-6 - Body ground Tire Pressure Warning System B
      3F-5 - Body ground SFI System, Automatic Transaxle System, Wiper and Washer System, Navigation System, Audio/visual System C

    B:  Go to step  11

    C:  Go to step  12

    A: Go to next step 

  10. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU CIRCUIT) 
    1. Disconnect the E59 connector
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      E59-9 (SPD) - Body ground Always 10 kΩ or higher
      Fig 9: Identifying E59 Connector Terminals
      G05837861Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE MAIN BODY ECU 

  11. CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU CIRCUIT) 
    1. Disconnect the E81 connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      E81-2 (SPD) Body ground Always 10 kΩ or higher
      Fig 10: Identifying E81 Connector Terminals
      G05837862Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE TIRE PRESSURE WARNING ECU 

  12. SYSTEM CHECK 
    1. Select the circuit in which is not present voltage in step  8.

      Result 

      RESULT CHART

      Tester Connection System That Uses the Circuit Proceed to
      4E-7 - Body ground SFI System A
      4E-7 - Body ground Automatic Transaxle System B
      4J-7 - Body ground Wiper and Washer System ((1)) C
      4G-7 - Body ground Navigation System ((2)) D
      4D-7 - Body ground Audio/Visual System ((3)) E
      (1) with Auto Wiper System
      (2) with Navigation System
      (3) for Separate Type Amplifier System

    B:  Go to step  14

    C:  Go to step  15

    D:  Go to step  16

    E:  Go to step  17

    A: Go to next step 

  13. CHECK HARNESS AND CONNECTOR (ECM CIRCUIT) 
    1. Disconnect the A10 connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      A10-8 (SPD) - Body ground Always 10 kΩ or higher
      Fig 11: Identifying A10 ECM Connector Terminals
      G05837863Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE ECM 

  14. CHECK HARNESS AND CONNECTOR (TCM CIRCUIT) 
    1. Disconnect the B40 connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      C56-3 (SPD1) - Body ground Always 10 kΩ or higher
      Fig 12: Identifying TCM B40 Connector Terminals
      G05837864Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE TCM 

  15. CHECK HARNESS AND CONNECTOR (WINDSHIELD WIPER RELAY CIRCUIT) 
    1. Disconnect the E11 connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      E11-19 (SPD) - Body ground Always 10 kΩ or higher
      Fig 13: Identifying E11 Connector Terminals
      G05837865Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE WINDSHIELD WIPER RELAY 

  16. CHECK HARNESS AND CONNECTOR (MULTI-DISPLAY CIRCUIT) 
    1. Disconnect the E62 connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      E62-14 (SPD) - Body ground Always 10 kΩ or higher
      Fig 14: Identifying E62 Connector Terminals
      G05837866Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE MULTI-DISPLAY 

  17. CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER CIRCUIT) 
    1. Disconnect the M30 connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      M30-11 (SPD) - Body ground Always 10 kΩ or higher
      Fig 15: Identifying M30 Connector Terminals
      G05837867Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE STEREO COMPONENT AMPLIFIER 

  18. CHECK HARNESS AND CONNECTOR (COMBINATION METER - SKID CONTROL ECU) 
    1. Disconnect the E20 connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      A36-12 (SP1) - E20-14 (SI) Always Below 1 Ω
      A36-12 (SP1) - Body ground Always 10 kΩ or higher
      Fig 16: Identifying E20 And A36 Connector Terminals
      G05837868Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE COMBINATION METER ASSEMBLY 

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