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DTC B2303: Communication Error from Backup Relay (BURDIAG1) to Sub Battery Module [12/2017 - 10/2023]: Procedure

  1. CHECK CONNECTOR CONNECTION CONDITION (SUB-BATTERY MODULE ASSEMBLY) 
    1. Refer to the following procedures for removing the connector cover from the luggage compartment mat sub-assembly.

      Refer to PROCEDURE - Step 11 [12/2017 - 09/2018] , or refer to PROCEDURE - Step 11 [09/2018 - 10/2020] , or refer to PROCEDURE - Step 8 [10/2020 - 10/2022] , or refer to PROCEDURE - Step 8 [10/2022 - 10/2023]

    2. Check the connection condition of the sub-battery module assembly connector and the contact pressure of the terminal. Check the terminals for deformation, and check the connector for water ingress and foreign matter.
      GTY780595Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK

      - The connector is connected securely.

      - The terminals are not deformed and are connected securely.

      - No water or foreign matter in each connector.

      Result

      Result Proceed to
      OK A
      NG (The connector is not connected securely.) B
      NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in a connector.) C

    Result: 

    B 

    CONNECT SECURELY 

    Result: 

    C 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    A 

    See step  2

  2. CHECK CONNECTOR CONNECTION CONDITION (BACKUP RELAY) 
    1. Refer to the following procedures for removing the backup relay from the luggage compartment mat sub-assembly.

      Refer to PROCEDURE - Step 11 [12/2017 - 09/2018] , or refer to PROCEDURE - Step 11 [09/2018 - 10/2020] , or refer to PROCEDURE - Step 8 [10/2020 - 10/2022] , or refer to PROCEDURE - Step 8 [10/2022 - 10/2023]

    2. Check the connection condition of the backup relay connector and the contact pressure of the terminal. Check the terminal for deformation, and check the connector for water ingress and foreign matter.
      GTY780596Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK

      - The connector is connected securely.

      - The terminals are not deformed and are connected securely.

      - No water or foreign matter in each connector.

      Result

      Result Proceed to
      OK A
      NG (The connector is not connected securely.) B
      NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in a connector.) C

    Result: 

    B 

    CONNECT SECURELY 

    Result: 

    C 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    A 

    See step  3

  3. CHECK DTC OUTPUT 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Clear the DTCs.

      Body Electrical > Sub Battery Module > Clear DTCs 

    5. Turn the engine switch off and wait for at least 30 seconds.
    6. Turn the engine switch on (IG) and wait for at least 15 seconds or more. (A)
    7. Turn the engine switch off and wait for at least 30 seconds. (B)
    8. Repeat steps (A) through (B) shown above at least 3 times.
    9. Turn the engine switch on (IG).
    10. Turn the Techstream on.
    11. Enter the following menus: Body Electrical / Sub Battery Module / Trouble Codes.

      Body Electrical > Sub Battery Module > Trouble Codes 

    12. Read the DTCs.

      Result

      Result Proceed to
      DTC B2303 is output A
      DTC B2303 and B2304 are output B
      DTC is not output C

    Result: 

    B 

    See step  11

    Result: 

    C 

    END 

    Result: 

    A 

    See step  4

  4. CHECK FREEZE FRAME DATA (DTC SUB CODE) 
    1. Check the DTC sub code displayed in the freeze frame data.

      Result

      Result Proceed to
      "3B" is output A
      "3C" is output B
      "3D" is output C

    Result: 

    B 

    See step  7

    Result: 

    C 

    See step  9

    Result: 

    A 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (SUB-BATTERY MODULE ASSEMBLY - BACKUP RELAY) 
    1. Disconnect the sub-battery module assembly connector.
    2. Disconnect the backup relay connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      P6-12 (RD1) - 6D-3 (RD11) Always Below 1 Ω
      P6-12 (RD1) or 6D-3 (RD11) - Other terminals Always 10 kΩ or higher
    4. Reconnect the sub-battery module assembly connector.
    5. Reconnect the backup relay connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  6

  6. INSPECT BACKUP RELAY 
    1. Disconnect the sub-battery module assembly connector
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.
      GTY795091Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Rear view of wire harness connector
      (to Sub-battery Module Assembly)

      Standard Voltage

      Tester Connection Condition Specified Condition
      P6-12 (RD1) - Body ground Engine switch on (IG) 0 to 1 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE SUB-BATTERY MODULE ASSEMBLY. Refer to  REMOVAL [12/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023] 

    Result: 

    NG 

    REPLACE BACKUP RELAY. Refer to  REMOVAL [12/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023] 

  7. INSPECT SUB-BATTERY MODULE ASSEMBLY 
    1. Disconnect the backup relay connector
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.
      GTY798212Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Backup Relay)

      Standard Voltage

      Tester Connection Condition Specified Condition
      6D-3 (RD11) - Body ground Engine switch on (IG) 7 to 14 V
    4. Reconnect the backup relay connector

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE BACKUP RELAY. Refer to  REMOVAL [12/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023] 

    Result: 

    NG 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (SUB-BATTERY MODULE ASSEMBLY - BACKUP RELAY) 
    1. Disconnect the sub-battery module assembly connector.
    2. Disconnect the backup relay connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      P6-12 (RD1) - 6D-3 (RD11) Always Below 1 Ω
      P6-12 (RD1) or 6D-3 (RD11) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE SUB-BATTERY MODULE ASSEMBLY. Refer to  REMOVAL [12/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  9. CHECK HARNESS AND CONNECTOR (SUB-BATTERY MODULE ASSEMBLY - BACKUP RELAY) 
    1. Disconnect the sub-battery module assembly connector.
    2. Disconnect the backup relay connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      P6-12 (RD1) - 6D-3 (RD11) Always Below 1 Ω
      P6-12 (RD1) or 6D-3 (RD11) - Body ground and other terminals Always 10 kΩ or higher
    4. Reconnect the sub-battery module assembly connector.
    5. Reconnect the backup relay connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  10

  10. INSPECT SUB-BATTERY MODULE ASSEMBLY 
    GTY799868Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *a Component with harness connected
    (Sub-battery Module Assembly)    		 *b Sub-battery Module Assembly
    1. Turn the engine switch on (IG).
    2. Inspect the sub-battery module assembly using an oscilloscope.
      GTY804634Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Reference waveform duty ratio: 78 to 82%
      Tester Connection Condition Equipment Setting
      P6-12 (RD1) - U2-1 (-BAT) Engine switch on (IG) 5 V/DIV., 10 msec./DIV.

      Result

      Result Proceed to
      Duty ratio of normal waveform is 38 to 42%, 58 to 62%, or 78 to 82% A
      No pulse waveforms or pulse output except those listed above B

    Result: 

    A 

    REPLACE SUB-BATTERY MODULE ASSEMBLY. Refer to  REMOVAL [12/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023] 

    Result: 

    B 

    REPLACE BACKUP RELAY. Refer to  REMOVAL [12/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023] 

  11. CHECK FREEZE FRAME DATA (DTC SUB CODE) 
    1. Check the DTC sub code displayed in the freeze frame data.

      Result

      Result Proceed to
      "3B" is displayed for the DTC Sub Code of B2303. A
      "3E" is displayed for the DTC Sub Code of B2304.
      "3C" is output B
      "3D" is output C

    Result: 

    B 

    See step  7

    Result: 

    C 

    See step  9

    Result: 

    A 

    See step  12

  12. CHECK HARNESS AND CONNECTOR (SUB-BATTERY MODULE ASSEMBLY - BACKUP RELAY) 
    1. Disconnect the sub-battery module connector.
    2. Disconnect the backup relay connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      P6-8 (BUR) - 6D-1 (RLY1) Always Below 1 Ω
      P6-8 (BUR) or 6D-1 (RLY1) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  13

  13. INSPECT SUB-BATTERY MODULE ASSEMBLY 
    1. Disconnect the backup relay connector
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.
      GTY969981Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Backup Relay)

      Standard Voltage

      Tester Connection Condition Specified Condition
      6D-1 (RLY1) - Body ground Engine switch on (IG) 0 to 1 V
    4. Reconnect the backup relay connector

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE BACKUP RELAY. Refer to  REMOVAL [12/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023] 

    Result: 

    NG 

    REPLACE SUB-BATTERY MODULE ASSEMBLY. Refer to  REMOVAL [12/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023] 

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