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 sensor signal*a. The vehicle speed sensor 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 the 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


  1. for 2GR-FE

    B000L7WE01

  2. for 2AR-FE

    B000J2HE01

  3. for 6AR-FSE

    B000IGKE01

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT ECU TERMINAL VOLTAGE (INPUT VOLTAGE)


    1. B000I88E38
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the I18 combination meter assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      I18-3 (+S) - Body ground Ignition switch ON 4.5 to 14 V

      Tech Tips

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


    NG

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

    OK

  2. INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE)


    1. Reconnect the I18 combination meter assembly connector.

    2. B000L6NE09
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Brake Actuator Assembly (Skid Control ECU))

      Disconnect the A49 brake actuator assembly (skid control ECU) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A49-2 (SP1) - Body ground Ignition switch ON 11 to 14 V

    NG

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

    OK

  3. INSPECT BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) (INPUT WAVEFORM)


    1. B000KN3E51
      Text in Illustration
      *a

      Component with harness connected

      (Combination Meter Assembly)

      Check the input waveform.


      1. Reconnect the A49 brake actuator assembly (skid control ECU) connector.

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

      3. Connect an oscilloscope to terminal I18-4 (SI) and body ground.

      4. Turn the ignition switch to ON.

      5. Turn the wheel slowly.

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

        Item Condition
        Tool setting 5 V/DIV., 20 ms/DIV.
        Vehicle condition Ignition switch ON, wheel being rotated
        OK
        The waveform is displayed as shown in the illustration.

        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.


    B

    REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) Click here

    A

    REPLACE COMBINATION METER ASSEMBLY Click here

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


    1. Disconnect the I18 combination meter assembly and A49 brake actuator assembly (skid control ECU) connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A49-2 (SP1) - I18-4 (SI) Always Below 1 Ω
      A49-2 (SP1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

  5. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - JUNCTION CONNECTOR)


    1. Disconnect the I124 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I18-3 (+S) - I124-18 Always Below 1 Ω
      I18-3 (+S) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR)


    1. Check for a short in the circuit that is connected to the junction connector shown in the wiring diagram.

      Tech Tips

      If voltage is not present, it is possible that an ECU or circuit has a malfunction. The malfunctioning ECU or circuit will be diagnosed in the following steps.


      1. Disconnect the I124 junction connector.

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

        Standard Voltage
        Tester Connection Condition Specified Condition
        I124-21 - Body ground Ignition switch ON 4.5 to 14 V
        I124-19 - Body ground Ignition switch ON 4.5 to 14 V
        I124-20 - Body ground Ignition switch ON 4.5 to 14 V
        I124-16 - Body ground Ignition switch ON 4.5 to 14 V
        I124-17 - Body ground Ignition switch ON 4.5 to 14 V
        Result
        Result Proceed to
        Voltage is not present in one circuit. A
        Voltage is present in all the circuits. B

    B

    REPLACE JUNCTION CONNECTOR (INSTRUMENT PANEL WIRE)

    A

  7. SYSTEM CHECK


    1. Select the circuit for which voltage was not present in step 6.

      Result
      Tester Connection System that uses the circuit Proceed to
      I124-21 - Body ground Smart entry and start system*1 A
      I124-19 - Body ground Navigation system*2 B
      I124-20 - Body ground Auto wiper system*7 C
      I124-16 - Body ground SFI system, Automatic headlight beam level control system*6, U660E automatic transaxle system*3 D
      I124-17 - Body ground Audio and visual system*5 or Navigation system*4 E

      • *1: w/ Smart Entry and Start System

      • *2: for 10 Speakers

      • *3: for 2GR-FE

      • *4: for Navigation Receiver Type

      • *5: for Radio and Display Type

      • *6: w/ Automatic Headlight Beam Level Control System

      • *7: w/ Auto Wiper System


    B

    CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSEMBLY CIRCUIT) Click here

    C

    CHECK HARNESS AND CONNECTOR (WINDSHIELD WIPER RELAY ASSEMBLY CIRCUIT) Click here

    D

    CONFIRM VEHICLE TYPE Click here

    E

    CONFIRM VEHICLE TYPE Click here

    A

  8. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) CIRCUIT)


    1. Disconnect the I78 certification ECU (Smart key ECU assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I78-27 (SPD) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

  9. CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSEMBLY CIRCUIT)


    1. Disconnect the I69 stereo component amplifier assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I69-11 (SPD) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY Click here

  10. CHECK HARNESS AND CONNECTOR (WINDSHIELD WIPER RELAY ASSEMBLY CIRCUIT)


    1. Disconnect the I72 windshield wiper relay assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I72-24 (SPD) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE WINDSHIELD WIPER RELAY ASSEMBLY Click here

  11. CONFIRM VEHICLE TYPE


    1. Choose the model to be inspected.

      Result
      Result Proceed to
      for 2GR-FE A
      for 2AR-FE B
      for 6AR-FSE C

    B

    CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - EACH ECU) Click here

    C

    CHECK HARNESS AND CONNECTOR (ECM CIRCUIT) Click here

    A

  12. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - EACH ECU)


    1. Disconnect the A25 ECM connector.

    2. Disconnect the E7 TCM connector.

    3. Disconnect the A34 headlight leveling ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I124-16 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  13. INSPECT ECM (SHORT CIRCUIT IN ECM)


    1. Reconnect the E7 TCM connector.

    2. Reconnect the A34 headlight leveling ECU assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      I124-16 - Body ground Ignition switch ON 4.5 to 14 V

      Tech Tips

      If the result is as specified, there may be a short circuit in the ECM.


    NG

    INSPECT TCM (SHORT CIRCUIT IN TCM) Click here

    OK

    REPLACE ECM Click here

  14. INSPECT TCM (SHORT CIRCUIT IN TCM)


    1. Reconnect the A25 ECM connector.

    2. Disconnect the E7 TCM connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      I124-16 - Body ground Ignition switch ON 4.5 to 14 V

      Tech Tips

      If the result is as specified, there may be a short circuit in the TCM.


    NG

    REPLACE HEADLIGHT LEVELING ECU ASSEMBLY Click here

    OK

    REPLACE TCM Click here

  15. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - EACH ECU)


    1. Disconnect the A25 ECM connector.

    2. Disconnect the A34 headlight leveling ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I124-16 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  16. INSPECT ECM (SHORT CIRCUIT IN ECM)


    1. Reconnect the A34 headlight leveling ECU assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      I124-16 - Body ground Ignition switch ON 4.5 to 14 V

      Tech Tips

      If the result is as specified, there may be a short circuit in the ECM.


    NG

    REPLACE HEADLIGHT LEVELING ECU ASSEMBLY Click here

    OK

    REPLACE ECM Click here

  17. CHECK HARNESS AND CONNECTOR (ECM CIRCUIT)


    1. Disconnect the A84 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A84-44 (SPD) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here

  18. CONFIRM VEHICLE TYPE


    1. Choose the model to be inspected.

      Result
      Result Proceed to
      except TMMK Made A
      for TMMK Made B

    B

    CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER ASSEMBLY CIRCUIT, RADIO AND DISPLAY RECEIVER ASSEMBLY CIRCUIT) Click here

    A

  19. CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER ASSEMBLY CIRCUIT, RADIO AND DISPLAY RECEIVER ASSEMBLY CIRCUIT, RADIO RECEIVER ASSEMBLY CIRCUIT)


    1. Disconnect the I67 navigation receiver assembly*1 connector, I155 radio and display receiver assembly*2 connector or I150 radio receiver assembly*3 connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I67-17 (SPD)*1 - Body ground Always 10 kΩ or higher
      I155-17 (SPD)*2 - Body ground Always 10 kΩ or higher
      I150-17 (SPD)*3 - Body ground Always 10 kΩ or higher

      • *1: for Navigation Receiver Type

      • *2: for Radio and Display Type

      • *3: for Radio Receiver Type

      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

    REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY Click here

    C

    REPLACE RADIO RECEIVER ASSEMBLY Click here

    D

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

    REPLACE NAVIGATION RECEIVER ASSEMBLY Click here

  20. CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER ASSEMBLY CIRCUIT, RADIO AND DISPLAY RECEIVER ASSEMBLY CIRCUIT)


    1. Disconnect the I67 navigation receiver assembly*1 connector or I155 radio and display receiver assembly*2 connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I67-17 (SPD)*1 - Body ground Always 10 kΩ or higher
      I155-17 (SPD)*2 - Body ground Always 10 kΩ or higher

      • *1: for Navigation Receiver Type

      • *2: for Radio and Display Type

      Result
      Result Proceed to
      OK (for Navigation Receiver Type) A
      OK (for Radio and Display Type) B
      NG C

    B

    REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

    REPLACE NAVIGATION RECEIVER ASSEMBLY Click here