METER / GAUGE SYSTEM > Speed Signal Circuit

for Preparation Click here


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 skid control ECU, which uses this information to create the vehicle speed sensor signal*1. The vehicle speed sensor signal consists of pulses sent to the combination meter assembly from the 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 skid control ECU. The pulse signal is created by switching the transistor in the 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 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.
  1. *1: This vehicle speed sensor signal is created by the skid control ECU. There is no actual component that is referred to as the vehicle speed sensor. In addition, for some other systems, vehicle speed information may be exchanged using CAN communication.

HINT:
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


E177358E01


INSPECTION PROCEDURE

1.INSPECT COMBINATION METER ASSEMBLY (INPUT VOLTAGE)


    E174446E02

  1. Disconnect the D1 combination meter assembly connector.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D1-16 (+S) - Body ground
    		Ignition switch ON
    		4.5 to 14 V

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Combination Meter Assembly)

    HINT:
    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.

  1. Reconnect the combination meter assembly connector.



NG
Go to step 5
OK


2.INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE)


    E177359E01

  1. Disconnect the A16 or A17 brake actuator assembly connector.

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

    Standard Voltage:
    for LHD 
    Tester Connection
    		Switch Condition
    		Specified Condition
    A16-11 (SP1) - Body ground
    		Ignition switch ON
    		11 to 14 V
    for RHD 
    Tester Connection
    		Switch Condition
    		Specified Condition
    A17-11 (SP1) - Body ground
    		Ignition switch ON
    		11 to 14 V

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Brake Actuator Assembly)
    *2
    		for LHD
    *3
    		for RHD

  1. Reconnect the brake actuator assembly connector.



NG
Go to step 4
OK


3.INSPECT BRAKE ACTUATOR ASSEMBLY (INPUT WAVEFORM)


    E174457E01

  1. Check the input waveform.

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

    2. Connect an oscilloscope to terminal D1-17 (SI) and body ground.

    3. Turn the ignition switch to ON.

    4. Turn the wheel slowly.

    5. 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
      		Driving at approx. 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.

      Text in Illustration 
      *1
      		Component with harness connected
      (Combination Meter Assembly)



NG
REPLACE BRAKE ACTUATOR ASSEMBLY (Click here)
OK

REPLACE COMBINATION METER ASSEMBLY (Click here)  

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


    E177360E01

  1. Disconnect the D1 combination meter assembly connector.

  1. Disconnect the A16 or A17 brake actuator assembly connector.

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

    Standard Resistance:
    for LHD 
    Tester Connection
    		Condition
    		Specified Condition
    A16-11 (SP1) - D1-17 (SI)
    		Always
    		Below 1 Ω
    A16-11 (SP1) - Body ground
    		Always
    		10 kΩ or higher
    for RHD 
    Tester Connection
    		Condition
    		Specified Condition
    A17-11 (SP1) - D1-17 (SI)
    		Always
    		Below 1 Ω
    A17-11 (SP1) - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Combination Meter Assembly)
    *2
    		Front view of wire harness connector
    (to Brake Actuator Assembly)
    *3
    		for LHD
    *4
    		for RHD

  1. Reconnect the combination meter assembly connector.

  1. Reconnect the brake actuator assembly connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE COMBINATION METER ASSEMBLY (Click here)  

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


    E174449E01

  1. Disconnect the D68 junction block connector.

  1. Disconnect the D1 combination meter assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    D1-16 (+S) - D68-71
    		Always
    		Below 1 Ω
    D1-16 (+S) - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Junction Block)
    *2
    		Front view of wire harness connector
    (to Combination Meter Assembly)

  1. Reconnect the junction block connector.

  1. Reconnect the combination meter assembly connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


6.INSPECT ECM


    E174450E01

  1. Disconnect the D68 junction block connector.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D68-61 - Body ground
    		Ignition switch ON
    		4.5 to 14 V

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Junction Block)

  1. Reconnect the junction block connector.



NG
Go to step 11
OK


7.INSPECT WINDSHIELD WIPER RELAY ASSEMBLY


    E174450E01

  1. Disconnect the D68 junction block connector.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D68-81 - Body ground
    		Ignition switch ON
    		4.5 to 14 V

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Junction Block)

  1. Reconnect the junction block connector.



NG
Go to step 12
OK


8.INSPECT POWER MANAGEMENT CONTROL ECU


    E174450E01

  1. Disconnect the D68 junction block connector.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D68-91 - Body ground
    		Ignition switch ON
    		4.5 to 14 V

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Junction Block)

  1. Reconnect the junction block connector.



NG
Go to step 13
OK


9.INSPECT POWER SOURCE CONTROL ECU


    E174450E01

  1. Disconnect the D68 junction block connector.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D68-91 - Body ground
    		Ignition switch ON
    		4.5 to 14 V

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Junction Block)

  1. Reconnect the junction block connector.



NG
Go to step 14
OK


10.INSPECT ENGINE STOP AND START ECU


    E174450E01

  1. Disconnect the D68 junction block connector.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D68-92 - Body ground
    		Ignition switch ON
    		4.5 to 14 V

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Junction Block)



NG
Go to step 15
OK

REPLACE JUNCTION BLOCK 

11.CHECK HARNESS AND CONNECTOR (JUNCTION BLOCK - ECM)


    E177361E01

  1. Disconnect the D68 junction block connector.

  1. Disconnect the A18 or A19 ECM connector.

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

    Standard Resistance:
    for 1KR-FE 
    Tester Connection
    		Condition
    		Specified Condition
    D68-61 - A18-38 (SPD)
    		Always
    		Below 1 Ω
    D68-61 - Body ground
    		Always
    		10 kΩ or higher
    for 1NR-FE 
    Tester Connection
    		Condition
    		Specified Condition
    D68-61 - A18-38 (SPD)
    		Always
    		Below 1 Ω
    D68-61 - Body ground
    		Always
    		10 kΩ or higher
    for 1ND-TV 
    Tester Connection
    		Condition
    		Specified Condition
    D68-61 - A19-25 (SPD)
    		Always
    		Below 1 Ω
    D68-61 - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Junction Block)
    *2
    		Front view of wire harness connector
    (to ECM)
    *3
    		Front view of wire harness connector
    (to ECM)
    *4
    		for 1KR-FE
    *5
    		for 1NR-FE
    *6
    		for 1ND-TV
    Result 
    Result
    		Proceed to
    NG
    		A
    OK (for 1KR-FE)
    		B
    OK (for 1NR-FE)
    		C
    OK (for 1ND-TV)
    		D

  1. Reconnect the junction block connector.

  1. Reconnect the ECM connector.



B
REPLACE ECM (Click here)

C
REPLACE ECM (Click here)

D
REPLACE ECM (Click here)
A

REPAIR OR REPLACE HARNESS OR CONNECTOR 

12.CHECK HARNESS AND CONNECTOR (JUNCTION BLOCK - WINDSHIELD WIPER RELAY ASSEMBLY)


    E177362E01

  1. Disconnect the D68 junction block connector.

  1. Disconnect the D41 windshield wiper relay assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    D68-81 - D41-19 (SPD)
    		Always
    		Below 1 Ω
    D68-81 - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Junction Block)
    *2
    		Front view of wire harness connector
    (to Windshield Wiper Relay Assembly)

  1. Reconnect the junction block connector.

  1. Reconnect the windshield wiper relay assembly connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE WINDSHIELD WIPER RELAY ASSEMBLY (Click here)  

13.CHECK HARNESS AND CONNECTOR (JUNCTION BLOCK - POWER MANAGEMENT CONTROL ECU)


    E174453E01

  1. Disconnect the D68 junction block connector.

  1. Disconnect the D38 power management control ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    D68-91 - D38-23 (SPD)
    		Always
    		Below 1 Ω
    D68-91 - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Junction Block)
    *2
    		Front view of wire harness connector
    (to Power Management Control ECU)

  1. Reconnect the junction block connector.

  1. Reconnect the power management control ECU connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE POWER MANAGEMENT CONTROL ECU (Click here)  

14.CHECK HARNESS AND CONNECTOR (JUNCTION BLOCK - POWER SOURCE CONTROL ECU)


    E174453E02

  1. Disconnect the D68 junction block connector.

  1. Disconnect the D73 power source control ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    D68-91 - D73-23 (SPD)
    		Always
    		Below 1 Ω
    D68-91 - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Junction Block)
    *2
    		Front view of wire harness connector
    (to Power Source Control ECU)

  1. Reconnect the junction block connector.

  1. Reconnect the power source control ECU connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE POWER SOURCE CONTROL ECU (Click here)  

15.CHECK HARNESS AND CONNECTOR (JUNCTION BLOCK - ENGINE STOP AND START ECU)


    E190529E01

  1. Disconnect the D68 junction block connector.

  1. Disconnect the D78 engine stop and start ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    D68-92 - D78-9 (SP1)
    		Always
    		Below 1 Ω
    D68-92 - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Junction Block)
    *2
    		Front view of wire harness connector
    (to Engine Stop and Start ECU)

  1. Reconnect the junction block connector.

  1. Reconnect the engine stop and start ECU connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ENGINE STOP AND START ECU (Click here)