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Taillight Circuit: Procedure

  1. CHECK TAILLIGHT (OPERATION) 
    1. Turn the engine switch on (IG).
    2. When the taillight switch is operated, check that the following lights illuminate.

      HINT: 

      • The front lights (front side marker lights and parking lights) share the same drive circuit. Therefore, if one of the front lights does not come on, there may be a problem in the circuit between the FR TAIL relay and bulb, or the circuit between the bulb and body ground. Inspect those circuits to identify the problem.
      • The rear lights (taillights, license plate lights, and side marker lights) share the same drive circuit. Therefore, if one of the rear lights does not come on, there may be a problem in the circuit between the TAIL relay and the bulb or LED, or the circuit between the bulb or LED and body ground. Inspect those circuits to identify the problem.

      Result

      Result Proceed to
      Neither front nor rear lights illuminate A
      Front lights (front side marker lights and parking lights) do not illuminate B
      Rear lights (taillights, license plate lights, and side marker lights) do not illuminate C

    C → See step   6 

    B → See step   2 

    A → See step   18 

  2. PERFORM ACTIVE TEST USING TECHSTREAM 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / Body No. 5 / Active Test.
    5. Check that the clearance lights operate.
      BODY NO. 5 (FRONT CONTROLLER)

      Tester Display Test Part Control Range Diagnostic Note
      Clearance Light Operation Clearance lights (Front side marker lights and parking lights) ON / OFF -

      OK

      Front side marker lights and parking lights illuminate.

    NG → See step   3 

    OK → REPLACE FRONT CONTROLLER (MULTIPLEX NETWORK BODY ECU) 

  3. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - BODY GROUND) 

    HINT: 

    Perform the following inspection on either the LH or RH side.

    1. Disconnect the B2 or B12 headlight assembly connector.
      Fig 1: Identifying B12 And B2 Connector Terminals
      GTY264882Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Headlight Assembly)
      *2 LH Side
      *3 RH Side
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      RH SIDE

      Tester Connection Condition Specified Condition
      B2-5 (E) - Body ground Always Below 1 Ω
      B2-8 (E) - Body ground Always Below 1 Ω
      LH SIDE

      Tester Connection Condition Specified Condition
      B12-5 (E) - Body ground Always Below 1 Ω
      B12-8 (E) - Body ground Always Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - FRONT CONTROLLER) 

    HINT: 

    Perform the following inspection on either the LH or RH side.

    1. Disconnect the B2 or B12 headlight assembly connector.
      Fig 2: Identifying B12 And B2 Connector Terminals
      GTY284015Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Headlight Assembly)
      *2 LH Side
      *3 RH Side
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      RH SIDE

      Tester Connection Condition Specified Condition
      B2-6 (B) - Body ground Light control switch off Below 1 V
      B2-6 (B) - Body ground Light control switch in tail position 11 to 14 V
      B2-7 (B) - Body ground Light control switch off Below 1 V
      B2-7 (B) - Body ground Light control switch in tail position 11 to 14 V
      LH SIDE

      Tester Connection Condition Specified Condition
      B12-6 (B) - Body ground Light control switch off Below 1 V
      B12-6 (B) - Body ground Light control switch in tail position 11 to 14 V
      B12-7 (B) - Body ground Light control switch off Below 1 V
      B12-7 (B) - Body ground Light control switch in tail position 11 to 14 V

    NG → See step   5 

    OK → See step   19 

  5. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - FRONT CONTROLLER) 

    HINT: 

    Perform the following inspection on either the LH or RH side.

    1. Disconnect the B2 or B12 headlight assembly connector.
      Fig 3: Identifying B12, B2 And 2G Connector Terminals
      GTY256417Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Headlight Assembly)
      *2 Front view of wire harness connector
      (to Front Controller)
      *3 LH Side
      *4 RH Side
    2. Disconnect the 2G front controller connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      RH SIDE

      Tester Connection Condition Specified Condition
      B2-6 (B) - 2G-10 Always Below 1 Ω
      B2-6 (B) - Body ground Always 10 kΩ or higher
      B2-7 (B) - 2G-8 Always Below 1 Ω
      B2-7 (B) - Body ground Always 10 kΩ or higher
      LH SIDE

      Tester Connection Condition Specified Condition
      B12-6 (B) - 2G-11 Always Below 1 Ω
      B12-6 (B) - Body ground Always 10 kΩ or higher
      B12-7 (B) - 2G-9 Always Below 1 Ω
      B12-7 (B) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → REPLACE FRONT CONTROLLER (MULTIPLEX NETWORK BODY ECU) 

  6. PERFORM ACTIVE TEST USING TECHSTREAM 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / Body / Active Test.
    5. Check the operation.
      BODY (MAIN BODY ECU RH)

      Tester Display Test Part Control Range Diagnostic Note
      Tail Light Taillights (taillights, license plate lights and side marker lights) ON/OFF -

      OK

      Taillights, license plate lights and side marker lights illuminate.

      Result

      Result Proceed to
      Inner taillights (rear light assembly) do not illuminate A
      Outer taillights and side marker lights (rear combination light assembly) do not illuminate B
      License plate lights do not illuminate C
      All rear lights illuminate D
      All rear lights do not illuminate E

      HINT: 

      If the outer taillights illuminate normally, but the side marker lights do not illuminate, or vice versa, there is an open circuit in the rear combination light assembly.

    E → See step   15 

    D → REPLACE MAIN BODY ECU RH (COWL SIDE JUNCTION BLOCK RH) 

    C → See step   11 

    B → See step   9 

    A: Go to next step 

  7. CHECK HARNESS AND CONNECTOR (REAR LIGHT ASSEMBLY - BODY GROUND) 

    HINT: 

    Perform the following inspection on either the LH or RH side.

    1. Disconnect the h1 or h6 rear light assembly connector.
      Fig 4: Identifying h1 And h6 Connector Terminals
      GTY267585Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Rear Light Assembly)
      *2 LH Side
      *3 RH Side
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      RH SIDE

      Tester Connection Condition Specified Condition
      h6-4 - Body ground Always Below 1 Ω
      LH SIDE

      Tester Connection Condition Specified Condition
      h1-4 - Body ground Always Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  8. CHECK HARNESS AND CONNECTOR (REAR LIGHT ASSEMBLY - MAIN BODY ECU LH) 

    HINT: 

    Perform the following inspection on either the LH or RH side.

    1. Disconnect the h1 or h6 rear light assembly connector.
      Fig 5: Identifying h1 And h6 Connector Terminals
      GTY267585Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Rear Light Assembly)
      *2 LH Side
      *3 RH Side
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      RH SIDE

      Tester Connection Condition Specified Condition
      h6-2 - Body ground Light control switch off Below 1 V
      h6-2 - Body ground Light control switch in tail position 11 to 14 V
      LH SIDE

      Tester Connection Condition Specified Condition
      h1-2 - Body ground Light control switch off Below 1 V
      h1-2 - Body ground Light control switch in tail position 11 to 14 V

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → REPLACE REAR LIGHT ASSEMBLY 

  9. CHECK HARNESS AND CONNECTOR (REAR COMBINATION LIGHT ASSEMBLY - BODY GROUND) 

    HINT: 

    Perform the following inspection on either the LH or RH side.

    1. Disconnect the Q51 or Q50 rear combination light assembly connector.
      Fig 6: Identifying Q50 And Q51 Connector Terminals
      GTY273440Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Rear Combination Light Assembly)
      *2 LH Side
      *3 RH Side
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      RH SIDE

      Tester Connection Condition Specified Condition
      Q51-6 (E) - Body ground Always Below 1 Ω
      LH SIDE

      Tester Connection Condition Specified Condition
      Q50-6 (E) - Body ground Always Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  10. CHECK HARNESS AND CONNECTOR (REAR COMBINATION LIGHT ASSEMBLY - MAIN BODY ECU LH) 

    HINT: 

    Perform the following inspection on either the LH or RH side.

    1. Disconnect the Q51 or Q50 rear combination light assembly connector.
      Fig 7: Identifying Q50 And Q51 Connector Terminals
      GTY273441Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Rear Combination Light Assembly)
      *2 LH Side
      *3 RH Side
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      RH SIDE

      Tester Connection Condition Specified Condition
      Q51-3 - Body ground Light control switch off Below 1 V
      Q51-3 - Body ground Light control switch in tail position 11 to 14 V
      LH SIDE

      Tester Connection Condition Specified Condition
      Q50-3 - Body ground Light control switch off Below 1 V
      Q50-3 - Body ground Light control switch in tail position 11 to 14 V

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → REPLACE REAR COMBINATION LIGHT ASSEMBLY 

  11. CHECK HARNESS AND CONNECTOR (LICENSE PLATE LIGHT ASSEMBLY LH - BODY GROUND) 

    HINT: 

    Perform the following inspection on the LH side.

    1. Disconnect the h2 license plate light assembly LH connector.
      Fig 8: Identifying h2 Connector Terminals
      GTY281200Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Licence Plate Light Assembly LH)
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      h2-2 (E) - Body ground Always Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  12. CHECK HARNESS AND CONNECTOR (LICENSE PLATE LIGHT ASSEMBLY LH - MAIN BODY ECU LH) 

    HINT: 

    Perform the following inspection on the LH side.

    1. Disconnect the h2 license plate light assembly LH connector.
      Fig 9: Identifying h2 Connector Terminals
      GTY281201Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Licence Plate Light Assembly LH)
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      h2-1 (B) - Body ground Light control switch off Below 1 V
      h2-1 (B) - Body ground Light control switch in tail position 5.5 to 7 V

    NG → See step   13 

    OK → REPLACE LICENSE PLATE LIGHT ASSEMBLY LH 

  13. CHECK HARNESS AND CONNECTOR (LICENSE PLATE LIGHT ASSEMBLY RH - MAIN BODY ECU LH) 

    HINT: 

    Perform the following inspection on the RH side.

    1. Disconnect the h3 license plate light assembly RH connector.
      Fig 10: Identifying h3 Connector Terminals
      GTY281202Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Licence Plate Light Assembly RH)
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      h3-1 (B) - Body ground Light control switch off Below 1 V
      h3-1 (B) - Body ground Light control switch in tail position 11 to 14 V

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  14. CHECK HARNESS AND CONNECTOR (LICENSE PLATE LIGHT ASSEMBLY LH - LIGHT ASSEMBLY RH) 
    1. Disconnect the h3 license plate light assembly RH connector.
      Fig 11: Identifying h3 And h2 Connector Terminals
      GTY281203Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to License Plate Light Assembly)
      *2 LH Side
      *3 RH Side
    2. Disconnect the h2 license plate light assembly LH connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      h3-2 (E) - h2-1 (B) Always Below 1 Ω
      h3-2 (E) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → REPLACE LICENSE PLATE LIGHT ASSEMBLY RH 

  15. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - BATTERY) 
    1. Disconnect the RD main body ECU RH connector.
      Fig 12: Identifying RD Connector Terminals
      GTY264176Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Main Body ECU RH)
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      RD-1 (TRLY) - Body ground Always 11 to 14 V

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  16. INSPECT MAIN BODY ECU RH (COWL SIDE JUNCTION BLOCK RH) 
    1. Connect the RD main body ECU RH connector.
      Fig 13: Identifying RD Connector Terminals
      GTY262168Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Component with harness connected
      (Main Body ECU RH)
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      RD-1 (TRLY) - Body ground Light control switch off Below 1 V
      RD-1 (TRLY) - Body ground Light control switch in tail position 11 to 14 V

    NG → REPLACE MAIN BODY ECU RH (COWL SIDE JUNCTION BLOCK RH) 

    OK: Go to next step 

  17. INSPECT MAIN BODY ECU LH (COWL SIDE JUNCTION BLOCK LH) 
    1. Measure the voltage according to the value(s) in the table below.
      Fig 14: Identifying LJ Connector Terminals
      GTY282415Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Component with harness connected
      (Main Body ECU LH)

      Standard Voltage

      Tester Connection Condition Specified Condition
      LJ-24 - Body ground Light control switch off Below 1 V
      LJ-24 - Body ground Light control switch in tail position 11 to 14 V

    NG → REPLACE MAIN BODY ECU LH (COWL SIDE JUNCTION BLOCK LH) 

    OK → REPAIR OR REPLACE HARNESS OR CONNECTOR (MAIN BODY ECU LH - EACH REAR LIGHT) 

  18. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE 
  19. REPLACE HEADLIGHT ASSEMBLY. Refer to  COMPONENTS 
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