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DTC C1A4B: Stop Light Relay Circuit [05/2019 - 07/2020]: Procedure

  1. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) CONNECTOR) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
      GTY697918Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Skid control ECU (Brake booster with master cylinder assembly))
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A32-37 (STP2) - Body ground Brake pedal depressed 11 to 14 V
      Brake pedal released Below 1.5 V
      A32-22 (STPO) - Body ground Power switch ON 11 to 14 V
      A32-12 (STP) - Body ground Brake pedal depressed 11 to 14 V
      Brake pedal released Below 1.5 V
    4. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Result Proceed to
      The voltage is as specified for every terminal. A
      Only the voltage at terminal STP2 is not as specified. B
      Only the voltage at terminal STPO is not as specified. C
      Only the voltage at terminal STP is not as specified. D
      The voltage at both terminal STPO and terminal STP are not as specified. E

    Result: 

    B 

    See step  5

    Result: 

    C 

    See step  12

    Result: 

    D 

    See step  14

    Result: 

    E 

    See step  23

    Result: 

    A 

    See step  2

  2. PERFORM ACTIVE TEST USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Turn the power switch off.
    2. According to the display on the Techstream, perform the Active Test Stop Light Relay.

      Refer to DATA LIST / ACTIVE TEST [09/2016 - ]

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      Stop Light Relay Stop light relay (Stop light switch assembly) ON / OFF Test possible at vehicle speed of 0 km/h (0 mph)

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display
      Stop Light Relay

      OK

      The stop lights turn on and off correctly in response to the operation of the Active Test.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  4

    Result: 

    OK 

    See step  3

  3. CHECK FOR DTCS (PRE-COLLISION SYSTEM) 
    1. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [09/2016 - 07/2020]

      Body Electrical > Pre-Collision 2 > Clear DTCs 

    2. According to the display on the Techstream, perform the Active Test Stop Light Relay.

      Refer to DATA LIST / ACTIVE TEST [09/2016 - ]

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      Stop Light Relay Stop light relay (Stop light switch assembly) ON / OFF Test possible at vehicle speed of 0 km/h (0 mph)

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display
      Stop Light Relay
    3. Check for DTCs.

      Refer to DTC CHECK / CLEAR [09/2016 - 07/2020]

      Body Electrical > Pre-Collision 2 > Trouble Codes 

      OK

      DTC C1A4B is not output

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [05/2019 - 07/2020] 

    Result: 

    NG 

    REPLACE SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY). Refer to  COMPONENTS [09/2016 - ] 

  4. INSPECT SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) 
    1. According to the display on the Techstream, perform the Active Test Stop Light Relay.

      Refer to DATA LIST / ACTIVE TEST [09/2016 - ]

      Chassis > ABS/VSC/TRAC > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      Stop Light Relay Stop light relay (Stop light switch assembly) ON / OFF Test possible at vehicle speed of 0 km/h (0 mph)

      Chassis > ABS/VSC/TRAC > Active Test 

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

      HINT: 

      Do not disconnect the stop light relay (stop light switch assembly) connector.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A66-4 (ACC) - Body ground Power switch on (IG)
      (Active test ON)      		 Below 1.5 V
      GTY939702Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Stop light relay (stop light switch assembly))

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY). Refer to  COMPONENTS [09/2016 - ] 

    Result: 

    NG 

    REPLACE SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY). Refer to  COMPONENTS [09/2016 - ] 

  5. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) CONNECTOR) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
      GTY697854Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Skid control ECU (Brake booster with master cylinder assembly))
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A32-37 (STP2) - Body ground Brake pedal released Below 1.5 V
    4. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  9

    Result: 

    OK 

    See step  6

  6. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the N54 certification ECU (smart key ECU assembly) connector.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A32-37 (STP2) or N54-25 (STP1) - Body ground Brake pedal depressed 11 to 14 V
    5. Connect the N54 certification ECU (smart key ECU assembly) connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  COMPONENTS [09/2016 - ] 

    Result: 

    NG 

    See step  7

  7. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - HYBRID VEHICLE CONTROL ECU) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the A41 hybrid vehicle control ECU connector.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A32-37 (STP2) or A41-7 (STP) - Body ground Brake pedal depressed 11 to 14 V
    5. Connect the A41 hybrid vehicle control ECU connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE HYBRID VEHICLE CONTROL ECU. Refer to  COMPONENTS [09/2016 - ] 

    Result: 

    NG 

    See step  8

  8. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY)) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the A66 stop light relay (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
      A32-37 (STP2) - A66-3 (L) Always Below 1 Ω
      A32-37 (STP2) or A66-3 (L) - Body ground Always 10 kΩ or higher
    5. Connect the A66 stop light relay (stop light switch assembly) connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY). Refer to  COMPONENTS [09/2016 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  9. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY)) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the A66 stop light relay (stop light switch assembly) connector.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A32-37 (STP2) or A66-3 (L) - Body ground Brake pedal released Below 1.5 V
    5. Connect the A66 stop light relay (stop light switch assembly) connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY). Refer to  COMPONENTS [09/2016 - ] 

    Result: 

    NG 

    See step  10

  10. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the N54 certification ECU (smart key ECU assembly) connector.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A32-37 (STP2) or N54-25 (STP1) - Body ground Brake pedal released Below 1.5 V
    5. Connect the N54 certification ECU (smart key ECU assembly) connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  COMPONENTS [09/2016 - ] 

    Result: 

    NG 

    See step  11

  11. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - HYBRID VEHICLE CONTROL ECU) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the A41 hybrid vehicle control ECU connector.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A32-37 (STP2) or A41-7 (STP) - Body ground Brake pedal released Below 1.5 V
    5. Connect the A41 hybrid vehicle control ECU connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE HYBRID VEHICLE CONTROL ECU. Refer to  COMPONENTS [09/2016 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  12. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY)) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the A66 stop light relay (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
      A32-22 (STPO) - A66-4 (ACC) Always Below 1 Ω
    5. Connect the A66 stop light relay (stop light switch assembly) connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  13

  13. INSPECT STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY) (POWER SOURCE CIRCUIT) 
    1. Turn the power switch off.
    2. Disconnect the A66 stop light relay (stop light switch assembly) connector.
      GTY880175Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Stop light relay (Stop light switch assembly))
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A66-6 (B) - Body ground Power switch ON 11 to 14 V
      A66-7 (B) - Body ground Always 11 to 14 V
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A66-2 (GND) - Body ground Always Below 1 Ω
    5. Connect the A66 stop light relay (stop light switch assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY). Refer to  COMPONENTS [09/2016 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  14. INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) CONNECTOR) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
      GTY697853Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Skid control ECU (Brake booster with master cylinder assembly))
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A32-12 (STP) - Body ground Brake pedal released Below 1.5 V
    4. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  19

    Result: 

    OK 

    See step  15

  15. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - REAR COMBINATION LIGHT ASSEMBLY LH) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the N37 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
      A32-12 (STP) or N37-3 (STP) - Body ground Brake pedal depressed 11 to 14 V
    5. Connect the N37 rear combination light assembly LH connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE REAR COMBINATION LIGHT ASSEMBLY LH. Refer to  COMPONENTS [05/2019 - 07/2020] 

    Result: 

    NG 

    See step  16

  16. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - REAR COMBINATION LIGHT ASSEMBLY RH) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the N36 rear combination light assembly RH connector.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A32-12 (STP) or N36-3 (STP) - Body ground Brake pedal depressed 11 to 14 V
    5. Connect the N36 rear combination light assembly RH connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE REAR COMBINATION LIGHT ASSEMBLY RH. Refer to  COMPONENTS [05/2019 - 07/2020] 

    Result: 

    NG 

    See step  17

  17. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - CENTER STOP LIGHT SET) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the R7 center stop light set connector.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A32-12 (STP) or R7-1 (B) - Body ground Brake pedal depressed 11 to 14 V
    5. Connect the R7 center stop light set connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CENTER STOP LIGHT SET. Refer to  COMPONENTS [09/2016 - ] 

    Result: 

    NG 

    See step  18

  18. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY)) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the A66 stop light relay (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
      A32-12 (STP) - A66-1 (OUT) Always Below 1 Ω
      A32-12 (STP) or A66-1 (OUT) - Body ground Always 10 kΩ or higher
    5. Connect the A66 stop light relay (stop light switch assembly) connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY). Refer to  COMPONENTS [09/2016 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  19. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY)) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the A66 stop light relay (stop light switch assembly) connector.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A32-12 (STP) or A66-1 (OUT) - Body ground Brake pedal released Below 1.5 V
    5. Connect the A66 stop light relay (stop light switch assembly) connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY). Refer to  COMPONENTS [09/2016 - ] 

    Result: 

    NG 

    See step  20

  20. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - REAR COMBINATION LIGHT ASSEMBLY LH) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the N37 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
      A32-12 (STP) or N37-3 (STP) - Body ground Brake pedal released Below 1.5 V
    5. Connect the N37 rear combination light assembly LH connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE REAR COMBINATION LIGHT ASSEMBLY LH. Refer to  COMPONENTS [05/2019 - 07/2020] 

    Result: 

    NG 

    See step  21

  21. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - REAR COMBINATION LIGHT ASSEMBLY RH) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the N36 rear combination light assembly RH connector.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A32-12 (STP) or N36-3 (STP) - Body ground Brake pedal released Below 1.5 V
    5. Connect the N36 rear combination light assembly RH connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE REAR COMBINATION LIGHT ASSEMBLY RH. Refer to  COMPONENTS [05/2019 - 07/2020] 

    Result: 

    NG 

    See step  22

  22. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - CENTER STOP LIGHT SET) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the R7 center stop light set connector.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A32-12 (STP) or R7-1 (B) - Body ground Brake pedal released Below 1.5 V
    5. Connect the R7 center stop light set connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CENTER STOP LIGHT SET. Refer to  COMPONENTS [09/2016 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  23. INSPECT STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY) (POWER SOURCE CIRCUIT) 
    1. Turn the power switch off.
    2. Disconnect the A66 stop light relay (stop light switch assembly) connector.
      GTY880175Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Stop light relay (Stop light switch assembly))
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A66-6 (B) - Body ground Power switch ON 11 to 14 V
      A66-7 (B) - Body ground Always 11 to 14 V
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A66-2 (GND) - Body ground Always Below 1 Ω
    5. Connect the A66 stop light relay (stop light switch assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  24

  24. CHECK WIRE HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY)) 
    1. Turn the power switch off.
    2. Disconnect the A32 skid control ECU (brake booster with master cylinder assembly) connector.
    3. Disconnect the A66 stop light relay (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
      A32-22 (STPO) or A66-4 (ACC) - Body ground Always 10 kΩ or higher
    5. Connect the A66 stop light relay (stop light switch assembly) connector.
    6. Connect the A32 skid control ECU (brake booster with master cylinder assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY). Refer to  COMPONENTS [09/2016 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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