METER / GAUGE SYSTEM Speed Signal Circuit

DESCRIPTION

The combination meter assembly receives the vehicle speed signal from this circuit. The wheel speed sensors produce an output that varies according to the vehicle speed. The wheel speed sensor output is received by the brake actuator assembly (skid control ECU) which uses this information to create the vehicle speed signal*. The vehicle speed signal consists of pulses sent to the combination meter assembly from the brake actuator assembly (skid control ECU). To create this signal, 12 V is output from IG2 which is behind a resistor in the combination meter assembly. This voltage is sent to the brake actuator assembly (skid control ECU). The pulse signal is created by switching the transistor in the brake actuator assembly (skid control ECU) on and off, making the voltage on the wire drop to 0 V. A similar system is used for the output of this signal from the combination meter assembly via terminal +S. A voltage of 12 V or 5 V is applied to terminal +S from each ECU or relay that is connected to this terminal. The transistor in the combination meter assembly is controlled by the signal from the brake actuator assembly (skid control ECU). When this transistor is turned on, this transistor makes the voltage supplied by the various ECUs (via their respective internal resistors) drop to 0 V. Each ECU connected to terminal +S of the combination meter assembly controls its respective system based on this pulse signal.


Tech Tips

This circuit is used for the systems connected to terminal +S. This signal is not used for combination meter assembly operation. Combination meter assembly components such as the speedometer operate using data received via CAN communication.

WIRING DIAGRAM

B003MU8E01

CAUTION / NOTICE / HINT

Note


  • When replacing the combination meter assembly, make sure to replace it with a new one.

  • Depending on the parts that are replaced during vehicle inspection or maintenance, performing initialization, registration or calibration may be needed.

  • w/ Smart Entry and Start System:

    Before replacing the certification ECU (smart key ECU assembly), refer to the smart entry and start system.

    Click here

  • for Navigation Receiver Type:

    When replacing the navigation receiver assembly, it is necessary to perform the vehicle contract setting for Connected Services.

    Click here

  • for Audio and Display Type:

    When replacing the radio and display receiver assembly, it is necessary to perform the vehicle contract setting for Connected Services.

    Click here

PROCEDURE


  1. CHECK VEHICLE TYPE


    1. Check the vehicle type.

      Result
      Result Proceed to
      for A750 Series Transmission A
      except A750 Series Transmission B

    B

    GO TO STEP 3 Click here

    A

  2. CHECK TRANSMISSION CONTROL ECU ASSEMBLY


    • *1: w/ Smart Entry and Start System

    • *2: for Navigation receiver Type

    • *3: for Radio and Display Type

    • *4: for Radio Receiver Type


    1. B003R15C38
      *a

      Rear view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G140 ECM connector.

    3. Disconnect the G16 certification ECU (smart key ECU assembly) connector.*1

    4. Disconnect the G33 body ECU connector.

    5. Disconnect the G41 navigation receiver assembly connector.*2

    6. Disconnect the G100 radio and display receiver assembly connector.*3

    7. Disconnect the G171 radio receiver assembly connector.*4

    8. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G8-19 (+S) - Body ground Ignition switch ON 4.5 to 14 V
      Result
      Result
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - TRANSMISSION CONTROL ECU ASSEMBLY) Click here

    OK

  3. CHECK ECM


    • *1: for A750 Series Transmission

    • *2: w/ Smart Entry and Start System

    • *3: for Navigation receiver Type

    • *4: for Radio and Display Type

    • *5: for Radio Receiver Type


    1. B003R15C38
      *a

      Rear view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G147 transmission control ECU assembly connector.*1

    3. Disconnect the G16 certification ECU (smart key ECU assembly) connector.*2

    4. Disconnect the G33 body ECU connector.

    5. Disconnect the G41 navigation receiver assembly connector.*3

    6. Disconnect the G100 radio and display receiver assembly connector.*4

    7. Disconnect the G171 radio receiver assembly connector.*5

    8. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G8-19 (+S) - Body ground Ignition switch ON 4.5 to 14 V
      Result
      Result Proceed to
      OK (w/ Entry and Start System) A
      OK (w/o Entry and Start System) B
      NG C

    B

    GO TO STEP 5 Click here

    C

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM) Click here

    A

  4. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    • *1: for A750 Series Transmission

    • *2: for 1GR-FE

    • *3: for TR Series Engine

    • *4: for KD Series Engine

    • *5: for GD Series Engine

    • *6: for 5L-E

    • *7: for Navigation receiver Type

    • *8: for Radio and Display Type

    • *9: for Radio Receiver Type


    1. B003R15C38
      *a

      Rear view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G147 transmission control ECU assembly connector.*1

    3. Disconnect the G145*2, G142*3, G140*4, G49*5 or G160*6 ECM connector.

    4. Disconnect the G33 body ECU connector.

    5. Disconnect the G41 navigation receiver assembly connector.*7

    6. Disconnect the G100 radio and display receiver assembly connector.*8

    7. Disconnect the G171 radio receiver assembly connector.*9

    8. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G8-19 (+S) - Body ground Ignition switch ON 4.5 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - CERTIFICATION ECU [SMART KEY ECU ASSEMBLY]) Click here

    OK

  5. CHECK BODY ECU


    • *1: for A750 Series Transmission

    • *2: for 1GR-FE

    • *3: for TR Series Engine

    • *4: for KD Series Engine

    • *5: for GD Series Engine

    • *6: for 5L-E

    • *7: w/ Smart Entry and Start System

    • *8: for Navigation receiver Type

    • *9: for Radio and Display Type

    • *10: for Radio Receiver Type


    1. B003R15C38
      *a

      Rear view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G147 transmission control ECU assembly connector.*1

    3. Disconnect the G145*2, G142*3, G140*4, G49*5 or G160*6 ECM connector.

    4. Disconnect the G16 certification ECU (smart key ECU assembly) connector.*7

    5. Disconnect the G41 navigation receiver assembly connector.*8

    6. Disconnect the G100 radio and display receiver assembly connector.*9

    7. Disconnect the G171 radio receiver assembly connector.*10

    8. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G8-19 (+S) - Body ground Ignition switch ON 4.5 to 14 V
      Result
      Result Proceed to
      OK (for Navigation Receiver Type) A
      OK (for Radio and Display Type) B
      OK (for Radio Receiver Type) C
      NG D

    B

    CHECK RADIO AND DISPLAY RECEIVER ASSEMBLY Click here

    C

    CHECK RADIO RECEIVER ASSEMBLY Click here

    D

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BODY ECU) Click here

    A

  6. CHECK NAVIGATION RECEIVER ASSEMBLY


    • *1: for A750 Series Transmission

    • *2: for 1GR-FE

    • *3: for TR Series Engine

    • *4: for KD Series Engine

    • *5: for GD Series Engine

    • *6: for 5L-E

    • *7: w/ Smart Entry and Start System


    1. B003R15C38
      *a

      Rear view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G147 transmission control ECU assembly connector.*1

    3. Disconnect the G145*2, G142*3, G140*4, G49*5 or G160*6 ECM connector.

    4. Disconnect the G16 certification ECU (smart key ECU assembly) connector.*7

    5. Disconnect the G33 body ECU connector.

    6. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G8-19 (+S) - Body ground Ignition switch ON 4.5 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - NAVIGATION RECEIVER ASSEMBLY) Click here

    OK

  7. CHECK COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE)


    • *1: w/ VSC

    • *2: w/o VSC


    1. Disconnect the A4*1 or A68*2 brake actuator assembly (skid control ECU) connector.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage (w/ VSC)
      Tester Connection Switch Condition Specified Condition
      A4-14 (SP1) - Body ground Ignition switch ON 11 to 14 V
      Standard Voltage (w/o VSC)
      Tester Connection Switch Condition Specified Condition
      A68-22 (SP1) - Body ground Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE ACTUATOR ASSEMBLY [SKID CONTROL ECU]) Click here

    OK

  8. CHECK COMBINATION METER ASSEMBLY (INPUT WAVEFORM)


    1. B003JXTC10
      *a

      Component with harness connected

      (Combination Meter Assembly)
      *b Waveform

      Remove the combination meter assembly with the connector(s) still connected.

    2. Connect an oscilloscope to terminal G8-18 (SI) and body ground.

    3. Check the signal waveform according to the condition(s) in the table below.

      Measurement Condition
      Item Condition
      Tester Connection G8-18 (SI) - Body ground
      Tool Setting 5 V/DIV, 20 ms./DIV
      Vehicle Condition Driving at approximately 20 km/h (12 mph)

      Tech Tips

      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.

      OK
      The waveform displayed is as shown in the illustration.
      Result
      Result
      OK
      NG

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) w/ VSC: Click here
    REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) w/o VSC: Click here

  9. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - TRANSMISSION CONTROL ECU ASSEMBLY)


    • *1: w/ Smart Entry and Start System

    • *2: for Navigation receiver Type

    • *3: for Radio and Display Type

    • *4: for Radio Receiver Type


    1. Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G147 transmission control ECU assembly connector.

    3. Disconnect the G140 ECM connector.

    4. Disconnect the G16 certification ECU (smart key ECU assembly) connector.*1

    5. Disconnect the G33 body ECU connector.

    6. Disconnect the G41 navigation receiver assembly connector.*2

    7. Disconnect the G100 radio and display receiver assembly connector.*3

    8. Disconnect the G171 radio and display receiver assembly connector.*4

    9. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G8-19 (+S) - G147-25 (SPD1) Always Below 1 Ω
      G8-19 (+S) or G147-25 (SPD1) - Body ground Always 10 kΩ or higher
      Result
      Result
      OK
      NG

    OK

    REPLACE TRANSMISSION CONTROL ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  10. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - CERTIFICATION ECU [SMART KEY ECU ASSEMBLY])


    • *1: for A750 Series Transmission

    • *2: for 1GR-FE

    • *3: for TR Series Engine

    • *4: for KD Series Engine

    • *5: for GD Series Engine

    • *6: for 5L-E

    • *7: for Navigation receiver Type

    • *8: for Radio and Display Type

    • *9: for Radio Receiver Type


    1. Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G147 transmission control ECU assembly connector.*1

    3. Disconnect the G145*2, G142*3, G140*4, G49*5 or G160*6 ECM connector.

    4. Disconnect the G16 certification ECU (smart key ECU assembly) connector.

    5. Disconnect the G33 body ECU connector.

    6. Disconnect the G41 navigation receiver assembly connector.*7

    7. Disconnect the G100 radio and display receiver assembly connector.*8

    8. Disconnect the G171 radio receiver assembly connector.*9

    9. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G8-19 (+S) - G16-7 (SPD) Always Below 1 Ω
      G8-19 (+S) or G16-7 (SPD) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  11. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - NAVIGATION RECEIVER ASSEMBLY)


    • *1: for A750 Series Transmission

    • *2: for 1GR-FE

    • *3: for TR Series Engine

    • *4: for KD Series Engine

    • *5: for GD Series Engine

    • *6: for 5L-E

    • *7: w/ Smart Entry and Start System


    1. Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G147 transmission control ECU assembly connector.*1

    3. Disconnect the G145*2, G142*3, G140*4, G49*5 or G160*6 ECM connector.

    4. Disconnect the G16 certification ECU (smart key ECU assembly) connector.*7

    5. Disconnect the G33 body ECU connector.

    6. Disconnect the G41 navigation receiver assembly connector.

    7. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G8-19 (+S) - G41-17 (SPD) Always Below 1 Ω
      G8-19 (+S) or G41-17 (SPD) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NAVIGATION RECEIVER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  12. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE ACTUATOR ASSEMBLY [SKID CONTROL ECU])


    • *1: w/ VSC

    • *2: w/o VSC


    1. Disconnect the N34 combination meter assembly connector.

    2. Disconnect the A4 or A68 brake actuator assembly (skid control ECU) connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (w/ VSC)
      Tester Connection Condition Specified Condition
      G8-18 (SI) - A4-14 (SP1) Always Below 1 Ω
      G8-18 (SI) or A4-14 (SP1) - Body ground Always 10 kΩ or higher
      Standard Resistance (w/o VSC)
      Tester Connection Condition Specified Condition
      G8-18 (SI) - A68-22 (SP1) Always Below 1 Ω
      G8-18 (SI) or A68-22 (SP1) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  13. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)


    • *1: for A750 Series Transmission

    • *2: for 1GR-FE

    • *3: for TR Series Engine

    • *4: for KD Series Engine

    • *5: for GD Series Engine

    • *6: for 5L-E

    • *7: w/ Smart Entry and Start System

    • *8: for Navigation receiver Type

    • *9: for Radio and Display Type

    • *10: for Radio Receiver Type


    1. Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G147 transmission control ECU assembly connector.*1

    3. Disconnect the G145*2, G142*3, G140*4, G49*5 or G160*6 ECM connector.

    4. Disconnect the G16 certification ECU (smart key ECU assembly) connector.*7

    5. Disconnect the G33 body ECU connector.

    6. Disconnect the G41 navigation receiver assembly connector.*8

    7. Disconnect the G100 radio and display receiver assembly connector.*9

    8. Disconnect the G171 radio receiver assembly connector.*10

    9. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G8-19 (+S) - G49-10 (SPD) Always Below 1 Ω
      G8-19 (+S) or G49-10 (SPD) - Body ground Always 10 kΩ or higher
      Result
      Result
      OK
      NG

    OK

    REPLACE ECM for 1GR-FE: Click here
    REPLACE ECM for 2TR-FE: Click here
    REPLACE ECM for 1KD-FTV: Click here
    REPLACE ECM for 2KD-FTV: Click here
    REPLACE ECM for 1GD-FTV: Click here
    REPLACE ECM for 2GD-FTV: Click here
    REPLACE ECM for 5L-E: Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  14. CHECK RADIO AND DISPLAY RECEIVER ASSEMBLY


    • *1: for A750 Series Transmission

    • *2: for 1GR-FE

    • *3: for TR Series Engine

    • *4: for KD Series Engine

    • *5: for GD Series Engine

    • *6: for 5L-E

    • *7: w/ Smart Entry and Start System


    1. B003R15C38
      *a

      Rear view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G147 transmission control ECU assembly connector.*1

    3. Disconnect the G145*2, G142*3, G140*4, G49*5 or G160*6 ECM connector.

    4. Disconnect the G16 certification ECU (smart key ECU assembly) connector.*7

    5. Disconnect the G33 body ECU connector.

    6. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G8-19 (+S) - Body ground Ignition switch ON 4.5 to 14 V
      Result
      Proceed to
      OK
      NG

    OK

    GO TO STEP 7 Click here

    NG

  15. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - RADIO AND DISPLAY RECEIVER ASSEMBLY)


    • *1: for A750 Series Transmission

    • *2: for 1GR-FE

    • *3: for TR Series Engine

    • *4: for KD Series Engine

    • *5: for GD Series Engine

    • *6: for 5L-E

    • *7: w/ Smart Entry and Start System


    1. Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G147 transmission control ECU assembly connector.*1

    3. Disconnect the G145*2, G142*3, G140*4, G49*5 or G160*6 ECM connector.

    4. Disconnect the G16 certification ECU (smart key ECU assembly) connector.*7

    5. Disconnect the G33 body ECU connector.

    6. Disconnect the G100 radio and display receiver assembly connector.

    7. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G8-19 (+S) - G100-17 (SPD) Always Below 1 Ω
      G8-19 (+S) or G100-17 (SPD) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  16. CHECK RADIO RECEIVER ASSEMBLY


    • *1: for A750 Series Transmission

    • *2: for 1GR-FE

    • *3: for TR Series Engine

    • *4: for KD Series Engine

    • *5: for GD Series Engine

    • *6: for 5L-E

    • *7: w/ Smart Entry and Start System


    1. B003R15C38
      *a

      Rear view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G147 transmission control ECU assembly connector.*1

    3. Disconnect the G145*2, G142*3, G140*4, G49*5 or G160*6 ECM connector.

    4. Disconnect the G16 certification ECU (smart key ECU assembly) connector.*7

    5. Disconnect the G33 body ECU connector.

    6. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G8-19 (+S) - Body ground Ignition switch ON 4.5 to 14 V
      Result
      Proceed to
      OK
      NG

    OK

    GO TO STEP 7 Click here

    NG

  17. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - RADIO RECEIVER ASSEMBLY)


    • *1: for A750 Series Transmission

    • *2: for 1GR-FE

    • *3: for TR Series Engine

    • *4: for KD Series Engine

    • *5: for GD Series Engine

    • *6: for 5L-E

    • *7: w/ Smart Entry and Start System


    1. Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G147 transmission control ECU assembly connector.*1

    3. Disconnect the G145*2, G142*3, G140*4, G49*5 or G160*6 ECM connector.

    4. Disconnect the G16 certification ECU (smart key ECU assembly) connector.*7

    5. Disconnect the G33 body ECU connector.

    6. Disconnect the G171 radio receiver assembly connector.

    7. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G8-19 (+S) - G171-17 (SPD) Always Below 1 Ω
      G8-19 (+S) or G171-17 (SPD) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE RADIO RECEIVER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  18. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BODY ECU)


    • *1: for A750 Series Transmission

    • *2: for 1GR-FE

    • *3: for TR Series Engine

    • *4: for KD Series Engine

    • *5: for GD Series Engine

    • *6: for 5L-E

    • *7: w/ Smart Entry and Start System

    • *8: for Navigation receiver Type

    • *9: for Radio and Display Type

    • *10: for Radio Receiver Type


    1. Disconnect the G8 combination meter assembly connector.

    2. Disconnect the G147 transmission control ECU assembly connector.*1

    3. Disconnect the G145*2, G142*3, G140*4, G49*5 or G160*6 ECM connector.

    4. Disconnect the G16 certification ECU (smart key ECU assembly) connector.*7

    5. Disconnect the G33 body ECU connector.

    6. Disconnect the G41 navigation receiver assembly connector.*8

    7. Disconnect the G100 radio and display receiver assembly connector.*9

    8. Disconnect the G171 radio receiver assembly connector.*10

    9. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G8-19 (+S) - G33-5 (SPD) Always Below 1 Ω
      G8-19 (+S) or G33-5 (SPD) - Body ground Always 10 kΩ or higher
      Result
      Result
      OK
      NG

    OK

    REPLACE BODY ECU for LHD: Click here
    REPLACE BODY ECU for RHD: Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR