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Home >> Lexus >> 2018 >> LC 500h >> Repair and Diagnosis (Single Page) >> Restraints >> Air Bag, SRS >> Pedestrian Protection System - Diagnostic Codes (1 Of 2) >> Pedestrian Protection System >> DTC B16A7: Lost Communication with Pedestrian Protection Sensor Bus LH; DTC B16A8: Pedestrian Protection Sensor Bus Initialization Incomplete (LH) [05/2023 - ] >> Procedure
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DTC B16A7: Lost Communication with Pedestrian Protection Sensor Bus LH; DTC B16A8: Pedestrian Protection Sensor Bus Initialization Incomplete (LH) [05/2023 - ]: Procedure

  1. CHECK CONNECTION OF CONNECTORS 
    1. Turn the power switch off.
    2. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.
    3. Check that the connectors are properly connected to the airbag ECU assembly and pedestrian detection chamber assembly (pedestrian protection sensor LH).

      OK

      The connectors are properly connected.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    CONNECT CONNECTORS PROPERLY 

    Result: 

    OK 

    See step  2

  2. CHECK CONNECTORS 
    1. Disconnect the connectors from the airbag ECU assembly and pedestrian detection chamber assembly (pedestrian protection sensor LH).
      GTY1241612Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Pedestrian Detection Chamber Assembly (Pedestrian Protection Sensor LH)
      *2 Airbag ECU Assembly
      *3 Engine Room Main Wire
      *4 Floor Wire
    2. Check that the connectors (on the airbag ECU assembly side and pedestrian detection protection LH side) are not damaged.

      OK

      The connectors are not deformed or damaged.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE ENGINE ROOM MAIN WIRE OR FLOOR WIRE 

    Result: 

    OK 

    See step  3

  3. CHECK PEDESTRIAN PROTECTION SENSOR LH CIRCUIT 
    1. Turn the power switch on (IG).
      GTY1242687Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Pedestrian Detection Chamber Assembly (Pedestrian Protection Sensor LH)
      *2 Airbag ECU Assembly
      *3 Engine Room Main Wire
      *4 Floor Wire
      *5 Service Wire
      *a Front view of wire harness connector
      (to Pedestrian Detection Chamber Assembly [Pedestrian Protection Sensor LH])
      *b Front view of wire harness connector
      (to Airbag ECU Assembly)
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      A31-1 (PSL+) - Body ground Power switch on (IG) Below 1 V
      A31-2 (PSL-) - Body ground Power switch on (IG) Below 1 V
    3. Turn the power switch off.
    4. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.
    5. Using a service wire, connect terminals 21 (PSL+) and 22 (PSL-) of connector B.
      NOTE:

      Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      A31-1 (PSL+) - A31-2 (PSL-) Always Below 1 Ω
    7. Disconnect the service wire from connector B.
    8. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A31-1 (PSL+) - A31-2 (PSL-) Always 1 MΩ or higher
      A31-1 (PSL+) - Body ground Always 1 MΩ or higher
      A31-2 (PSL-) - Body ground Always 1 MΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  5

    Result: 

    OK 

    See step  4

  4. CHECK PEDESTRIAN PROTECTION SENSOR LH 
    1. Connect the connector to the airbag ECU assembly.
      GTY1242988Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Pedestrian Detection Chamber Assembly (Pedestrian Protection Sensor LH)
      *2 Airbag ECU Assembly
    2. Replace the pedestrian detection chamber assembly with a new one.

      Refer to REMOVAL [05/2023 - ]

    3. Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
    4. Turn the power switch on (IG), and wait for at least 60 seconds.
    5. Clear the DTCs stored in memory.

      Refer to DTC CHECK / CLEAR [04/2020 - ]

      Body Electrical > Pedestrian Protection > Clear DTCs 

    6. Turn the power switch off.
    7. Turn the power switch on (IG), and wait for at least 60 seconds.
    8. Check for DTCs.

      Refer to DTC CHECK / CLEAR [04/2020 - ]

      Body Electrical > Pedestrian Protection > Trouble Codes 

      Result

      Result Proceed to
      DTC B16A7 or B16A8 is not output A
      DTC B16A7 or B16A8 is output B

      HINT: 

      Codes other than B16A7 and B16A8 may be output at this time, but they are not related to this check.

    Result: 

    A 

    END (PEDESTRIAN DETECTION CHAMBER ASSEMBLY [PEDESTRIAN PROTECTION SENSOR LH] WAS DEFECTIVE) 

    Result: 

    B 

    REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL [05/2023 - ] 

  5. CHECK CONNECTORS 
    1. Disconnect the floor wire connector from the engine room main wire.
      GTY1242656Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Pedestrian Detection Chamber Assembly (Pedestrian Protection Sensor LH)
      *2 Airbag ECU Assembly
      *3 Engine Room Main Wire
      *4 Floor Wire
    2. Check that the connectors (on the engine room main wire side and floor wire side) are not damaged.

      OK

      The connectors are not deformed or damaged.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE ENGINE ROOM MAIN WIRE OR FLOOR WIRE 

    Result: 

    OK 

    See step  6

  6. CHECK FLOOR WIRE 
    1. Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
      GTY1242685Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Pedestrian Detection Chamber Assembly (Pedestrian Protection Sensor LH)
      *2 Airbag ECU Assembly
      *3 Engine Room Main Wire
      *4 Floor Wire
      *5 Service Wire
      *a Front view of wire harness connector
      (to Engine Room Main Wire)
      *b Front view of wire harness connector
      (to Airbag ECU Assembly)
    2. Turn the power switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      XA6-11 (PSL+) - Body ground Power switch on (IG) Below 1 V
      XA6-12 (PSL-) - Body ground Power switch on (IG) Below 1 V
    4. Turn the power switch off.
    5. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.
    6. Using a service wire, connect terminals 21 (PSL+) and 22 (PSL-) of connector B.
      NOTE:

      Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      XA6-11 (PSL+) - XA6-12 (PSL-) Always Below 1 Ω
    8. Disconnect the service wire from connector B.
    9. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      XA6-11 (PSL+) - XA6-12 (PSL-) Always 1 MΩ or higher
      XA6-11 (PSL+) - Body ground Always 1 MΩ or higher
      XA6-12 (PSL-) - Body ground Always 1 MΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ENGINE ROOM MAIN WIRE 

    Result: 

    NG 

    REPLACE FLOOR WIRE 

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