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Inspection Procedure

NOTE: When replacing the master cylinder solenoid, perform zero point calibration (See CALIBRATION  ).
  1. CHECK STOP LIGHT SWITCH OPERATION 
    1. Check that the stop light comes on when the brake pedal is depressed, and goes off when the brake pedal is released.

      OK: Stop light switch function is normal. 

      HINT: 

      Check the stop light bulb as it may have burnt out. 

    NG: Go to step  9

    OK: Go to next step 

  2. INSPECT SKID CONTROL ECU (STP TERMINAL) 
    1. Disconnect the skid control ECU connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Condition Specified Condition
      S37-7 (STP) - Body ground Stop light switch ON (Brake pedal depressed) 8 to 14 V
      S37-7 (STP) - Body ground Stop light switch OFF (Brake pedal released) Below 1.5 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT) 

    Fig 1: Identifying S37 Skid Control ECU Connector
    G05262752Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  3. INSPECT SKID CONTROL ECU (STP2 TERMINAL) 
    1. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      S37-7 (STP) - S37-45 (STP2) Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (STP2 CIRCUIT) 

    Fig 2: Identifying S37 Skid Control ECU Connector
    G05262753Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  4. PERFORM ACTIVE TEST BY TECHSTREAM (STOP LIGHT OPERATION RELAY) 
    1. Reconnect the skid control ECU connector.
    2. Connect Techstream to the DLC3.
    3. Turn the ignition switch to the ON position and push Techstream main switch ON.
    4. Select "Active Test" mode on Techstream.

      ABS/VSC/TRAC 

      DIAGNOSTIC NOTE

      Item Tester Part Control Range Diagnostic Note
      Stop Light Relay Turns stop light operation relay Relay ON/OFF Observe rear combination light (Does not come on for 5 seconds or more)
    5. Check that "ON" and "OFF" of the stop light can be shown on the rear combination light by Techstream.

      OK: The stop light turns on or off in accordance with Techstream. 

    OK: Go to step  8

    NG: Go to next step 

  5. INSPECT STOP LIGHT OPERATION RELAY (POWER SOURCE TERMINAL) 
    1. Remove the stop light operation (downhill assist control) relay.
    2. Turn the ignition switch to the ON position.
    3. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Condition Specified Condition
      1 - Body ground Ignition switch ON 8 to 14 V
      5 - Body ground Ignition switch ON 8 to 14 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) 

    Fig 3: Identifying Stop Light Operation (Downhill Assist Control) Relay
    G05262754Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  6. INSPECT STOP LIGHT OPERATION RELAY (DOWNHILL ASSIST CONTROL RELAY) 
    1. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      3 - 4 Below 1 Ω
      3 - 5 10 kΩ or higher
      3 - 4 10 kΩ or higher (When battery positive voltage is applied to terminal 1 and battery negative voltage to terminal 2.)
      3 - 5 Below 1 Ω (When battery positive voltage is applied to terminal 1 and battery negative voltage to terminal 2.)

    NG: REPLACE STOP LIGHT OPERATION RELAY (DOWNHILL ASSIST CONTROL RELAY) 

    Fig 4: Stop Light Operation Relay Circuit Diagram
    G04965497Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  7. INSPECT SKID CONTROL ECU (STPO TERMINAL) 
    1. Instal the stop light operation (downhill assist control) relay.
    2. Disconnect the skid control ECU connector.
    3. Turn the ignition switch to the ON position.
    4. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Condition Specified Condition
      S37-16 (STPO) - Body ground Ignition switch ON 10 to 14 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (STPO CIRCUIT) 

    Fig 5: Identifying S37 Skid Control ECU Connector
    G05262756Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  8. RECONFIRM DTC 
    1. Clear the DTC (See DTC CHECK/CLEAR  ).
    2. Check if the same DTC is detected (See DTC CHECK/CLEAR  ).

      HINT:

      Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

      Result 

      RESULT CHART

      Condition Proceed to
      DTC is output A
      DTC is not output B

    B: END 

    A: REPLACE MASTER CYLINDER SOLENOID 

  9. INSPECT STOP LIGHT SWITCH ASSEMBLY (POWER SOURCE TERMINAL) 
    1. Disconnect the stop light switch connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Condition Specified Condition
      S17-2 Body ground Always 10 to 14 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) 

    Fig 6: Inspecting Stop Light Switch Assembly (Power Source Terminal)
    G05262757Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  10. INSPECT STOP LIGHT SWITCH ASSEMBLY 
    1. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester connection Condition Specified condition
      S17-1 - S17-2 Switch pin free Below 1 Ω
      S17-1 - S17-2 Switch pin pushed in 10 kΩ or higher

    NG: REPLACE STOP LIGHT SWITCH ASSEMBLY 

    Fig 7: Inspecting Stop Light Switch Assembly
    G05262758Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  11. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - STOP LIGHT OPERATION RELAY) 
    1. Remove the stop light operation (downhill assist control) relay.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      S17-1 - Stop light operation (downhill assist control) relay 4 Below 1 Ω
      S17-1 - Body ground 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 8: Checking Harness And Connector (Stop Light Switch - Stop Light Operation Relay)
    G05262759Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  12. INSPECT STOP LIGHT OPERATION RELAY (DOWNHILL ASSIST CONTROL RELAY) 
    1. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      3 - 4 Below 1 Ω

    NG: REPLACE STOP LIGHT OPERATION RELAY (DOWNHILL ASSIST CONTROL RELAY) 

    Fig 9: Stop Light Operation Relay Circuit Diagram
    G04965497Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  13. CHECK HARNESS AND CONNECTOR (REAR COMBINATION LIGHT - STOP LIGHT OPERATION RELAY) 
    1. Disconnect the rear combination light connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance: 

      LH 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      R14-6 - Stop light operation (downhill assist control) relay 3 Below 1 Ω
      R14-6 - Body ground 10 kΩ or higher
      R14-5 - Body ground Below 1 Ω

      RH 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      R15-3 - Stop light operation (downhill assist control) relay 3 Below 1 Ω
      R15-3 - Body ground 10 kΩ or higher
      R15-5 - Body ground Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT CIRCUIT) 

    Fig 10: Checking Harness And Connector (Rear Combination Light - Stop Light Operation Relay)
    G05262761Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: END 

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