LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2019 >> NX 300 Base, AWD >> Repair and Diagnosis >> Restraints >> Restraints Control Systems >> Pre-Collision System - Diagnostic Codes & Circuit Tests >> Pre-Collision System >> DTC C1A4B: Stop Light Relay Circuit [09/2017 - 05/2019] >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC C1A4B: Stop Light Relay Circuit [09/2017 - 05/2019]: Procedure

  1. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) CONNECTOR) 
    1. Turn the engine switch off.
    2. Disconnect the skid control ECU (brake actuator assembly) connector.
      GTY806515Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Skid control ECU (brake actuator assembly))
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A36-35 (STP) - Body ground Brake pedal depressed 11 to 14 V
      Brake pedal released Below 1.5 V
      A36-26 (STPO) - Body ground Engine switch on (IG) 11 to 14 V
      A36-5 (STP2) - Body ground Brake pedal depressed 11 to 14 V
      Brake pedal released Below 1.5 V
    4. Connect the skid control ECU (brake actuator assembly) connector.

      Result

      Result Proceed to
      All terminal voltage is normal A
      Only STP terminal voltage abnormal B
      Only STPO terminal voltage abnormal C
      Only STP2 terminal voltage abnormal D
      STPO terminal and STP2 terminal voltage abnormal E

    Result: 

    B 

    See step  5

    Result: 

    C 

    See step  11

    Result: 

    D 

    See step  12

    Result: 

    E 

    See step  20

    Result: 

    A 

    See step  2

  2. PERFORM ACTIVE TEST USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Turn the engine switch off.
    2. Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.
    3. Perform "Active Test" according to the display on the Techstream.

      Refer to DATA LIST / ACTIVE TEST [10/2014 - 05/2019]

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      Stop Light Relay Stop light control ECU assembly ON or OFF Stop lights come on

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display
      Stop Light Relay

      OK

      Stop light turns ON/OFF in response to the Techstream operation

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  4

    Result: 

    OK 

    See step  3

  3. CHECK FOR DTC 
    1. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [09/2017 - 05/2019]

      Body Electrical > Pre-Collision 2 > Clear DTCs 

    2. Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.
    3. Perform "Active Test" according to the display on the Techstream.

      Refer to DATA LIST / ACTIVE TEST [10/2014 - 05/2019]

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      Stop Light Relay Stop light control ECU assembly ON or OFF Stop lights come on

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display
      Stop Light Relay
    4. Check for DTCs.

      Refer to DTC CHECK / CLEAR [09/2017 - 05/2019]

      Body Electrical > Pre-Collision 2 > Trouble Codes 

      Result

      Result Proceed to
      DTC C1A4B is output. A
      DTC C1A4B is not output. B

    Result: 

    A 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2017 - 05/2019] 

    Result: 

    B 

    REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY). Refer to  REMOVAL [10/2014 - 05/2019] 

  4. INSPECT SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) 
    1. Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.
    2. Perform "Active Test" according to the display on the Techstream.

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      Stop Light Relay Stop light control ECU assembly ON or OFF Stop lights come on

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display
      Stop Light Relay
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A3-9 (ACC) - Body ground Active Test is ON Below 1.5 V
      GTY800726Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected (Stop Light Switch Assembly)

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT CONTROL ECU ASSEMBLY. Refer to  REMOVAL [10/2014 - ] 

    Result: 

    NG 

    REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY). Refer to  REMOVAL [10/2014 - 05/2019] 

  5. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - ECM) 
    1. Turn the engine switch off.
    2. Disconnect the skid control ECU (brake actuator assembly) connector.
      GTY806516Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Skid control ECU (brake actuator assembly))
    3. Disconnect the A35 ECM connector.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A36-35 (STP) - Body ground Brake pedal depressed 8 to 14 V
      A36-35 (STP) - Body ground Brake pedal released Below 1.5 V
    5. Connect the A35 ECM connector.
    6. Connect the skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ECM. Refer to  REMOVAL [10/2014 - 05/2019] 

    Result: 

    NG 

    See step  6

  6. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - SHIFT LOCK CONTROL UNIT ASSEMBLY) 
    1. Turn the engine switch off.
    2. Disconnect the skid control ECU (brake actuator assembly) connector.
      GTY806516Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Skid control ECU (brake actuator assembly))
    3. Disconnect the A35 ECM connector.
    4. Disconnect the I22 shift lock control unit assembly connector.
    5. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A36-35 (STP) - Body ground Brake pedal depressed 8 to 14 V
      A36-35 (STP) - Body ground Brake pedal released Below 1.5 V
    6. Connect the I22 shift lock control unit assembly connector.
    7. Connect the A35 ECM connector.
    8. Connect the skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE SHIFT LOCK CONTROL UNIT ASSEMBLY. Refer to  DISASSEMBLY [10/2014 - ] 

    Result: 

    NG 

    See step  7

  7. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)) 
    1. Turn the engine switch off.
    2. Disconnect the skid control ECU (brake actuator assembly) connector.
      GTY806516Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Skid control ECU (brake actuator assembly))
    3. Disconnect the A35 ECM connector.
    4. Disconnect the I22 shift lock control unit assembly connector.
    5. Disconnect the I51 certification ECU (smart key ECU assembly) connector.
    6. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A36-35 (STP) - Body ground Brake pedal depressed 8 to 14 V
      A36-35 (STP) - Body ground Brake pedal released Below 1.5 V
    7. Connect the I51 certification ECU (smart key ECU assembly) connector.
    8. Connect the I22 shift lock control unit assembly connector.
    9. Connect the A35 ECM connector.
    10. Connect the skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 

    Result: 

    NG 

    See step  8

  8. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY) 
    1. Turn the engine switch off.
    2. Disconnect the skid control ECU (brake actuator assembly) connector.
      GTY806516Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Skid control ECU (brake actuator assembly))
    3. Disconnect the A35 ECM connector.
    4. Disconnect the I22 shift lock control unit assembly connector.
    5. Disconnect the I51 certification ECU (smart key ECU assembly) connector.
    6. Disconnect the A3 stop light control ECU assembly connector.
    7. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A36-35 (STP) - Body ground Brake pedal depressed 8 to 14 V
      A36-35 (STP) - Body ground Brake pedal released Below 1.5 V
    8. Connect the A3 stop light control ECU assembly connector.
    9. Connect the I51 certification ECU (smart key ECU assembly) connector.
    10. Connect the I22 shift lock control unit assembly connector.
    11. Connect the A35 ECM connector.
    12. Connect the skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT CONTROL ECU ASSEMBLY. Refer to  REMOVAL [10/2014 - ] 

    Result: 

    NG 

    See step  9

  9. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT SWITCH ASSEMBLY) 
    1. Turn the engine switch off.
    2. Disconnect the skid control ECU (brake actuator assembly) connector.
      GTY806516Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Skid control ECU (brake actuator assembly))
    3. Disconnect the A35 ECM connector.
    4. Disconnect the I22 shift lock control unit assembly connector.
    5. Disconnect the I51 certification ECU (smart key ECU assembly) connector.
    6. Disconnect the A3 stop light control ECU assembly connector.
    7. Disconnect the A1 stop light switch assembly connector.
    8. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A36-35 (STP) - Body ground Always Below 1.5 V
    9. Connect the A1 stop light switch assembly connector.
    10. Connect the A3 stop light control ECU assembly connector.
    11. Connect the I51 certification ECU (smart key ECU assembly) connector.
    12. Connect the I22 shift lock control unit assembly connector.
    13. Connect the A35 ECM connector.
    14. Connect the skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  10

  10. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT SWITCH ASSEMBLY) 
    1. Turn the engine switch off.
    2. Disconnect the A36 skid control ECU (brake actuator assembly) connector.
    3. Disconnect the A1 stop light switch assembly connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A36-35 (STP) - A1-2 (L) Always Below 1 Ω
      A36-35 (STP) or A1-2 (L) - Body ground Always 10 kΩ or higher
    5. Connect the A1 stop light switch assembly connector.
    6. Connect the A36 skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to  REMOVAL [09/2016 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  11. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY) 
    1. Turn the engine switch off.
    2. Disconnect the A36 skid control ECU (brake actuator assembly) connector.
    3. Disconnect the A3 stop light control ECU assemblyconnector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A36-26 (STPO) - A3-9 (ACC) Always Below 1 Ω
    5. Connect the A3 stop light control ECU assemblyconnector.
    6. Connect the A36 skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT CONTROL ECU ASSEMBLY. Refer to  REMOVAL [10/2014 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  12. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - REAR COMBINATION LIGHT ASSEMBLY LH) 
    1. Turn the engine switch off.
    2. Disconnect the skid control ECU (brake actuator assembly) connector.
      GTY806514Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Skid control ECU (brake actuator assembly))
    3. Disconnect the Q16 rear combination light assembly LH connector.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A36-5 (STP2) - Body ground Brake pedal depressed 8 to 14 V
      A36-5 (STP2) - Body ground Brake pedal released Below 1.5 V
    5. Connect the Q16 rear combination light assembly LH connector.
    6. Connect the skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE REAR COMBINATION LIGHT ASSEMBLY LH. Refer to  REMOVAL [09/2017 - ] 

    Result: 

    NG 

    See step  13

  13. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - REAR COMBINATION LIGHT ASSEMBLY RH) 
    1. Turn the engine switch off.
    2. Disconnect the skid control ECU (brake actuator assembly) connector.
      GTY806514Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Skid control ECU (brake actuator assembly))
    3. Disconnect the Q16 rear combination light assembly LH connector.
    4. Disconnect the P13 rear combination light assembly RH connector.
    5. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A36-5 (STP2) - Body ground Brake pedal depressed 8 to 14 V
      A36-5 (STP2) - Body ground Brake pedal released Below 1.5 V
    6. Connect the P13 rear combination light assembly RH connector.
    7. Connect the Q16 rear combination light assembly LH connector.
    8. Connect the skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE REAR COMBINATION LIGHT ASSEMBLY RH. Refer to  REMOVAL [09/2017 - ] 

    Result: 

    NG 

    See step  14

  14. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - REAR LIGHT ASSEMBLY LH) 
    1. Turn the engine switch off.
    2. Disconnect the skid control ECU (brake actuator assembly) connector.
      GTY806514Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Skid control ECU (brake actuator assembly))
    3. Disconnect the Q16 rear combination light assembly LH connector.
    4. Disconnect the P13 rear combination light assembly RH connector.
    5. Disconnect the Y11 rear light assembly LH connector.
    6. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A36-5 (STP2) - Body ground Brake pedal depressed 8 to 14 V
      A36-5 (STP2) - Body ground Brake pedal released Below 1.5 V
    7. Connect the Y11 rear light assembly LH connector.
    8. Connect the P13 rear combination light assembly RH connector.
    9. Connect the Q16 rear combination light assembly LH connector.
    10. Connect the skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE REAR LIGHT ASSEMBLY LH. Refer to  REMOVAL [09/2017 - ] 

    Result: 

    NG 

    See step  15

  15. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - REAR LIGHT ASSEMBLY RH) 
    1. Turn the engine switch off.
    2. Disconnect the skid control ECU (brake actuator assembly) connector.
      GTY806514Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Skid control ECU (brake actuator assembly))
    3. Disconnect the Q16 rear combination light assembly LH connector.
    4. Disconnect the P13 rear combination light assembly RH connector.
    5. Disconnect the Y11 rear light assembly LH connector.
    6. Disconnect the Y10 rear light assembly RH connector.
    7. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A36-5 (STP2) - Body ground Brake pedal depressed 8 to 14 V
      A36-5 (STP2) - Body ground Brake pedal released Below 1.5 V
    8. Connect the Y10 rear light assembly RH connector.
    9. Connect the Y11 rear light assembly LH connector.
    10. Connect the P13 rear combination light assembly RH connector.
    11. Connect the Q16 rear combination light assembly LH connector.
    12. Connect the skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE REAR LIGHT ASSEMBLY RH. Refer to  REMOVAL [09/2017 - ] 

    Result: 

    NG 

    See step  16

  16. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - CENTER STOP LIGHT ASSEMBLY) 
    1. Turn the engine switch off.
    2. Disconnect the skid control ECU (brake actuator assembly) connector.
      GTY806514Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Skid control ECU (brake actuator assembly))
    3. Disconnect the Q16 rear combination light assembly LH connector.
    4. Disconnect the P13 rear combination light assembly RH connector.
    5. Disconnect the Y11 rear light assembly LH connector.
    6. Disconnect the Y10 rear light assembly RH connector.
    7. Disconnect the e1 center stop light assembly connector.
    8. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A36-5 (STP2) - Body ground Brake pedal depressed 8 to 14 V
      A36-5 (STP2) - Body ground Brake pedal released Below 1.5 V
    9. Connect the e1 center stop light assembly connector.
    10. Connect the Y10 rear light assembly RH connector.
    11. Connect the Y11 rear light assembly LH connector.
    12. Connect the P13 rear combination light assembly RH connector.
    13. Connect the Q16 rear combination light assembly LH connector.
    14. Connect the skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CENTER STOP LIGHT ASSEMBLY. Refer to  REMOVAL [10/2014 - ] 

    Result: 

    NG 

    See step  17

  17. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY) 
    1. Turn the engine switch off.
    2. Disconnect the skid control ECU (brake actuator assembly) connector.
      GTY806514Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Skid control ECU (brake actuator assembly))
    3. Disconnect the Q16 rear combination light assembly LH connector.
    4. Disconnect the P13 rear combination light assembly RH connector.
    5. Disconnect the Y11 rear light assembly LH connector.
    6. Disconnect the Y10 rear light assembly RH connector.
    7. Disconnect the e1 center stop light assembly connector.
    8. Disconnect the A3 stop light control ECU assembly connector.
    9. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A36-5 (STP2) - Body ground Always Below 1.5 V
    10. Connect the A3 stop light control ECU assembly connector.
    11. Connect the e1 center stop light assembly connector.
    12. Connect the Y10 rear light assembly RH connector.
    13. Connect the Y11 rear light assembly LH connector.
    14. Connect the P13 rear combination light assembly RH connector.
    15. Connect the Q16 rear combination light assembly LH connector.
    16. Connect the skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  18

  18. CHECK HARNESS AND CONNECTOR (+B/GND TERMINAL) 
    1. Turn the engine switch off.
      GTY784803Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Stop light control ECU assembly)
    2. Disconnect the A3 stop light control ECU assembly connector.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A3-6 (+B) - Body ground Always 11 to 14V
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A3-8 (GND) - Body ground Always Below 1 Ω
    5. Connect the A3 stop light control ECU assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  19

  19. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY) 
    1. Turn the engine switch off.
    2. Disconnect the A36 skid control ECU (brake actuator assembly) connector.
    3. Disconnect the A3 stop light control ECU assembly connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A3-1 (OUT) - A36-5 (STP2) Always Below 1 Ω
      A3-1 (OUT) or A36-5 (STP2) - Body ground Always 10 kΩ or higher
    5. Connect the A3 stop light control ECU assembly connector.
    6. Connect the A36 skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT CONTROL ECU ASSEMBLY. Refer to  REMOVAL [10/2014 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  20. CHECK HARNESS AND CONNECTOR (+B/GND TERMINAL) 
    1. Turn the engine switch off.
      GTY784804Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of harness connector
      (to Stop light control ECU assembly)
    2. Disconnect the A3 stop light control ECU assembly connector.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A3-6 (+B) - Body ground Always 11 to 14V
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A3-8 (GND) - Body ground Always Below 1 Ω
    5. Connect the A3 stop light control ECU assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  21

  21. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY) 
    1. Turn the engine switch off.
    2. Disconnect the A36 skid control ECU (brake actuator assembly) connector.
    3. Disconnect the A3 stop light control ECU assembly connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A3-1 (OUT) - A36-5 (STP2) Always Below 1 Ω
      A3-1 (OUT) or A36-5 (STP2) - Body ground Always 10 kΩ or higher
    5. Connect the A3 stop light control ECU assembly connector.
    6. Connect the A36 skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT CONTROL ECU ASSEMBLY. Refer to  REMOVAL [09/2016 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

scientia non olet · About LEMON Manuals