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DTC B1643: Side Satellite Sensor Bus RH Initialization Error

Diagnosis start condition: 

Ignition voltage is 10 V to 16 V.

DTC detecting condition: 

Side satellite sensor bus RH circuit is shorted, shorted to ground or shorted to power supply.

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Refer to AIRBAG SYSTEM (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION .

Wiring diagram: 

Airbag system Refer to WIRING SYSTEM>AIRBAG SYSTEM>WIRING DIAGRAM .

G12454258Courtesy of SUBARU OF AMERICA, INC.
  1. INSPECTION OF AIRBAG SYSTEM. 
    1. Perform the Inspection Mode. Refer to AIRBAG SYSTEM (DIAGNOSTICS)>INSPECTION MODE .
    2. Read the DTC. (Current malfunction) Refer to AIRBAG SYSTEM (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

    Is the airbag ECM malfunction, or DTC B1620, B1630, B1690 a current malfunction?

    Yes:  Perform the diagnosis for the displayed DTCs. Refer to AIRBAG SYSTEM (DIAGNOSTICS)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

    No:  Go to  2.

  2. CHECK POOR CONTACT OF CONNECTORS. 

    Check for poor contact of the connectors between the airbag control module and the front door impact sensor RH.

    Is there poor contact?

    Yes:  Replace the door harness RH, or replace the airbag rear harness along with body harness.

    No:  Go to  3.

  3. CHECK AIRBAG REAR HARNESS (BETWEEN AIRBAG CONTROL MODULE AND SIDE AIRBAG SENSOR RH). 
    1. Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 60 seconds or more.
    2. Disconnect the connector (AB26) from seat belt pretensioner RH.
    3. Disconnect the connector (AB33) from curtain airbag module RH.
    4. Disconnect the connector (AB24) of side airbag module RH.
    5. Disconnect the connector (AB30) from the lap seat belt pretensioner RH.
    6. Disconnect the connectors (AB6, AB17, AB18) from airbag control module.
    7. Disconnect the connector (AB28) from side airbag sensor RH, and connect the connector (2V) in test harness V to connector (AB28).
    8. Measure the resistance between connector (3V) in test harness V and chassis ground, and the resistance between test harness (3V) terminals.

      Connector & terminal 

      (3V) No. 1 - Chassis ground:

      (3V) No. 2 - Chassis ground:

      (3V) No. 1 - (3V) No. 2:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  4.

    No:  Replace the airbag rear harness along with body harness.

  4. CHECK AIRBAG REAR HARNESS (BETWEEN AIRBAG CONTROL MODULE AND SIDE AIRBAG SENSOR RH). 

    Measure the voltage between connector (3V) in the test harness V and chassis ground.

    Connector & terminal 

    (3V) No. 1 (+) - Chassis ground (-):

    (3V) No. 2 (+) - Chassis ground (-):

    Is the voltage less than 1 V?

    Yes:  Go to  5.

    No:  Replace the airbag rear harness along with body harness.

  5. CHECK AIRBAG REAR HARNESS (BETWEEN SIDE AIRBAG SENSOR RH AND CURTAIN AIRBAG SENSOR RH). 
    1. Disconnect the connector (2V) in the test harness V from the connector (AB28) of side airbag sensor RH.
    2. Connect the connector (AB28) of side airbag sensor RH and the connector (1AI) in the test harness AI.
    3. Connect the connector (2AI) in the test harness AI and the connector (1V) in the test harness V.
    4. Disconnect the connector (AB34) from curtain airbag sensor (RH), and connect the connector (2V) in test harness V to connector (AB34).
    5. Measure the resistance between connector (3V) in test harness V and chassis ground, and the resistance between connector (3V) terminals in test harness V.

      Connector & terminal 

      (3V) No. 1 - Chassis ground:

      (3V) No. 2 - Chassis ground:

      (3V) No. 1 - (3V) No. 2:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  6.

    No:  Replace the airbag rear harness along with body harness.

  6. CHECK AIRBAG REAR HARNESS (BETWEEN SIDE AIRBAG SENSOR RH AND CURTAIN AIRBAG SENSOR RH). 

    Measure the voltage between connector (3V) in the test harness V and chassis ground.

    Connector & terminal 

    (3V) No. 1 (+) - Chassis ground (-):

    (3V) No. 2 (+) - Chassis ground (-):

    Is the voltage less than 1 V?

    Yes:  Go to  7.

    No:  Replace the airbag rear harness along with body harness.

  7. CHECK AIRBAG REAR HARNESS AND DOOR HARNESS RH (BETWEEN CURTAIN AIRBAG SENSOR RH AND FRONT DOOR IMPACT SENSOR RH). 
    1. Disconnect the connector (AB64) from front door impact sensor RH.
    2. Measure the resistance between connector (3V) in test harness V and chassis ground, and the resistance between connector (3V) terminals in test harness V.

      Connector & terminal 

      (3V) No. 4 - Chassis ground:

      (3V) No. 5 - Chassis ground:

      (3V) No. 4 - (3V) No. 5:

    Is the resistance 1 MΩ or more?

    Yes:  Go to  9.

    No:  Go to  8.

  8. CHECK AIRBAG REAR HARNESS AND DOOR HARNESS RH (BETWEEN CURTAIN AIRBAG SENSOR RH AND FRONT DOOR IMPACT SENSOR RH). 
    1. Disconnect the connector (R124) in the airbag rear harness and the connector (AB63) of the door harness RH.
    2. Measure the resistance between connector (3V) in test harness V and chassis ground, and the resistance between connector (3V) terminals in test harness V.

      Connector & terminal 

      (3V) No. 4 - Chassis ground:

      (3V) No. 5 - Chassis ground:

      (3V) No. 4 - (3V) No. 5:

    Is the resistance 1 MΩ or more?

    Yes:  Replace the door harness RH.

    No:  Replace the airbag rear harness along with body harness.

  9. CHECK AIRBAG REAR HARNESS AND DOOR HARNESS RH (BETWEEN CURTAIN AIRBAG SENSOR RH AND FRONT DOOR IMPACT SENSOR RH). 

    Measure the voltage between connector (3V) in the test harness V and chassis ground.

    Connector & terminal 

    (3V) No. 4 (+) - Chassis ground (-):

    (3V) No. 5 (+) - Chassis ground (-):

    Is the voltage less than 1 V?

    Yes:  Go to  11.

    No:  Go to  10.

  10. CHECK AIRBAG REAR HARNESS AND DOOR HARNESS RH (BETWEEN CURTAIN AIRBAG SENSOR RH AND FRONT DOOR IMPACT SENSOR RH). 
    1. Disconnect the connector (R124) in the airbag rear harness and the connector (AB63) of the door harness RH.
    2. Measure the voltage between connector (3V) in the test harness V and chassis ground.

      Connector & terminal 

      (3V) No. 4 (+) - Chassis ground (-):

      (3V) No. 5 (+) - Chassis ground (-):

    Is the voltage less than 1 V?

    Yes:  Replace the door harness RH.

    No:  Replace the airbag rear harness along with body harness.

  11. REPLACE FRONT DOOR IMPACT SENSOR RH AND CHECK AIRBAG CONTROL MODULE AFTER REPLACEMENT. 
    1. Replace the front door impact sensor RH. Refer to AIRBAG SYSTEM>FRONT DOOR IMPACT SENSOR>REMOVAL .
    2. Connect all connectors.
    3. Connect the battery ground terminal and turn the ignition switch to ON.
    4. Clear the memory. Refer to AIRBAG SYSTEM (DIAGNOSTICS)>CLEAR MEMORY MODE .
    5. Perform the Inspection Mode. Refer to AIRBAG SYSTEM (DIAGNOSTICS)>INSPECTION MODE .
    6. Read the DTC. (Current malfunction) Refer to AIRBAG SYSTEM (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

    Is DTC B1643 a current malfunction?

    Yes:  Go to  12.

    No:  Finish the diagnosis.

  12. REPLACE CURTAIN AIRBAG SENSOR RH AND CHECK AIRBAG CONTROL MODULE AFTER REPLACEMENT. 
    1. Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 60 seconds or more.
    2. Replace the curtain airbag sensor RH. Refer to AIRBAG SYSTEM>CURTAIN AIRBAG SENSOR>REMOVAL .
    3. Connect the battery ground terminal and turn the ignition switch to ON.
    4. Clear the memory. Refer to AIRBAG SYSTEM (DIAGNOSTICS)>CLEAR MEMORY MODE .
    5. Perform the Inspection Mode. Refer to AIRBAG SYSTEM (DIAGNOSTICS)>INSPECTION MODE .
    6. Read the DTC. (Current malfunction) Refer to AIRBAG SYSTEM (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

    Is DTC B1643 a current malfunction?

    Yes:  Go to  13.

    No:  Finish the diagnosis.

  13. REPLACE SIDE AIRBAG SENSOR RH AND CHECK AIRBAG CONTROL MODULE AFTER REPLACEMENT. 
    1. Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 60 seconds or more.
    2. Replace the side airbag sensor RH. Refer to AIRBAG SYSTEM>SIDE AIRBAG SENSOR>REMOVAL .
    3. Connect the battery ground terminal and turn the ignition switch to ON.
    4. Clear the memory. Refer to AIRBAG SYSTEM (DIAGNOSTICS)>CLEAR MEMORY MODE .
    5. Perform the Inspection Mode. Refer to AIRBAG SYSTEM (DIAGNOSTICS)>INSPECTION MODE .
    6. Read the DTC. (Current malfunction) Refer to AIRBAG SYSTEM (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

    Is DTC B1643 a current malfunction?

    Yes:  Replace the airbag control module. Refer to AIRBAG SYSTEM>AIRBAG CONTROL MODULE>REMOVAL .

    No:  Finish the diagnosis.

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