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AIRBAG SYSTEM, Diagnostic DTC:B1638

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DTC Code DTC Name
B1638 Curtain Shield Airbag Sensor Initialization Error (LH)
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DESCRIPTION

The circuit for the side collision sensor LH is composed of the airbag ECU assembly, door side airbag sensor LH, side airbag sensor assembly LH and rear airbag sensor LH.

The rear airbag sensor LH detect impacts to the vehicle and send signals to the airbag ECU assembly to determine if the airbag should be deployed.

DTC B1638 is stored when a malfunction is detected in the circuit for the side collision sensor LH.

DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Test Mode / Check Mode
B1638 Curtain Shield Airbag Sensor Initialization Error (LH)

One of the following conditions is met:


  • The airbag ECU assembly detects a line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in the circuit for the side collision sensor LH for 2 seconds.

  • A rear airbag sensor LH malfunction.

  • An airbag ECU assembly malfunction.

  • Floor wire

  • Front door wire LH

  • Rear airbag sensor LH

  • Airbag ECU assembly

 Comes on Not applicable
Table 1. *a Rear Airbag Sensor LH *b Door Side Airbag Sensor LH *c Side Airbag Sensor Assembly LH *d Airbag ECU Assembly
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WIRING DIAGRAM

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CAUTION / NOTICE / HINT

Note:

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

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  • When disconnecting the cable from the negative (-) auxiliary battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected.

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PROCEDURE


  1. Click here

    CHECK PAST DTC


    1. Turn the power switch on (IG), and wait for at least 60 seconds.

    2. Check for DTCs.

      Click here


      1. Body Electrical > SRS Airbag > Trouble Codes


      Result
      Proceed to
      DTC B1637 is not output
      DTC B1637 is output

  2. Click here

    CHECK DTC


    1. Turn the power switch off.

      Tip:

      If a communication error occurs, DTCs for both the LH and RH sides will be stored simultaneously. The malfunctioning area can be identified by turning the power switch off and then on (IG) again.

    2. Turn the power switch on (IG), and wait for at least 60 seconds.

    3. Check for DTCs.

      Click here


      1. Body Electrical > SRS Airbag > Trouble Codes


      Result
      Proceed to
      DTC B1638 is output
      DTC B1638 is not output
      Tip:

      Codes other than DTC B1638 may be output at this time, but they are not related to this check.


  3. Click here

    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 rear airbag sensor LH.

      Result
      Proceed to
      The connectors are properly connected
      The connectors are not properly connected

    • The connectors are properly connectedClick here
    • The connectors are not properly connected

      CONNECT CONNECTORS PROPERLY

  4. Click here

    CHECK CONNECTORS


    1. Disconnect the connectors from the airbag ECU assembly and rear airbag sensor LH.

    2. B004TEOC32
      *1 Rear Airbag Sensor LH
      *2 Airbag ECU Assembly
      *3 Floor Wire

      Check that the connectors (on the airbag ECU assembly side and rear airbag sensor LH side) are not damaged.

      Result
      Proceed to
      The connectors are not deformed or damaged
      The connectors are deformed or damaged

    • The connectors are not deformed or damagedClick here
    • The connectors are deformed or damaged

      REPLACE FLOOR WIRE

  5. Click here

    CHECK FLOOR WIRE


    1. B004W2ZC07
      *1 Rear Airbag Sensor LH
      *2 Airbag ECU Assembly
      *3 Floor Wire
      *4 Service Wire
      *a

      Front view of wire harness connector

      (to Rear Airbag Sensor LH)
      *b

      Front view of wire harness connector

      (to Airbag ECU Assembly)

      Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.

    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
      L63-4 (BCL+) - Body ground Power switch on (IG) Below 1 V
      L63-3 (BCL-) - 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 32 (BBL+) and 31 (BBL-) 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
      L63-4 (BCL+) - L63-3 (BCL-) 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
      L63-4 (BCL+) - L63-3 (BCL-) Always 1 MΩ or higher
      L63-4 (BCL+) - Body ground Always 1 MΩ or higher
      L63-3 (BCL-) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

  6. Click here

    CHECK REAR AIRBAG SENSOR LH


    1. B004T4LC01
      *1 Rear Airbag Sensor RH
      *2 Airbag ECU Assembly

      Connect the connectors to the airbag ECU assembly.

    2. Interchange the rear airbag sensor LH with RH and connect the connectors to them.

    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.

      Click here


      1. Body Electrical > SRS Airbag > 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.

      Click here


      1. Body Electrical > SRS Airbag > Trouble Codes


      Result
      Proceed to
      DTC B1633 is output
      DTC B1638 is output
      DTC B1633 and B1638 are not output
      Tip:

      Codes other than DTC B1633 and B1638 may be output at this time, but they are not related to this check.

    9. Turn the power switch off.

    10. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.

    11. Return the rear airbag sensor RH and LH to their original positions and connect the connectors to them.


    • DTC B1633 is output

      REPLACE REAR AIRBAG SENSOR LHClick here

    • DTC B1638 is outputClick here
    • DTC B1633 and B1638 are not output

      USE SIMULATION METHOD TO CHECKClick here

  7. Click here

    CHECK CONNECTION OF CONNECTOR


    1. Check that the connector is properly connected to the side airbag sensor assembly LH.

      Result
      Proceed to
      The connector is properly connected
      The connector is not properly connected

    • The connector is properly connectedClick here
    • The connector is not properly connected

      CONNECT CONNECTOR PROPERLY

  8. Click here

    CHECK CONNECTOR


    1. Disconnect the connectors from the side airbag sensor assembly LH and rear airbag sensor LH.

    2. B004RO2C05
      *1 Side Airbag Sensor Assembly LH
      *2 Rear Airbag Sensor LH
      *3 Floor Wire

      Check that the connector (on the side airbag sensor assembly LH side) is not damaged.

      Result
      Proceed to
      The connector is not deformed or damaged
      The connector is deformed or damaged

    • The connector is not deformed or damagedClick here
    • The connector is deformed or damaged

      REPLACE FLOOR WIRE

  9. Click here

    CHECK FLOOR WIRE


    1. B004XT1C03
      *1 Side Airbag Sensor Assembly LH
      *2 Rear Airbag Sensor LH
      *3 Floor Wire
      *4 Service Wire
      *a

      Front view of wire harness connector

      (to Side Airbag Sensor Assembly LH)
      *b

      Front view of wire harness connector

      (to Rear Airbag Sensor LH)

      Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.

    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
      L66-4 (BBL+) - Body ground Power switch on (IG) Below 1 V
      L66-3 (BBL-) - 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 1 (BBL+) and 2 (BBL-) 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
      L66-4 (BBL+) - L66-3 (BBL-) 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
      L66-4 (BBL+) - L66-3 (BBL-) Always 1 MΩ or higher
      L66-4 (BBL+) - Body ground Always 1 MΩ or higher
      L66-3 (BBL-) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

  10. Click here

    CHECK CONNECTION OF CONNECTOR


    1. Check that the connector is properly connected to the door side airbag sensor LH.

      Result
      Proceed to
      The connector is properly connected
      The connector is not properly connected

    • The connector is properly connectedClick here
    • The connector is not properly connected

      CONNECT CONNECTOR PROPERLY

  11. Click here

    CHECK CONNECTOR


    1. Disconnect the connectors from the door side airbag sensor LH.

    2. B004YH5C08
      *1 Door Side Airbag Sensor LH
      *2 Side Airbag Sensor Assembly LH
      *3 Front Door Wire LH
      *4 Floor Wire

      Check that the connector (on the door side airbag sensor LH side) is not damaged.

      Result
      Proceed to
      The connector is not deformed or damaged
      The connector is deformed or damaged

    • The connector is not deformed or damagedClick here
    • The connector is deformed or damaged

      REPLACE FRONT DOOR WIRE LH

  12. Click here

    CHECK DOOR SIDE AIRBAG SENSOR LH CIRCUIT


    1. B004VY7C10
      *1 Door Side Airbag Sensor LH
      *2 Side Airbag Sensor Assembly LH
      *3 Front Door Wire LH
      *4 Floor Wire
      *5 Service Wire
      *a

      Front view of wire harness connector

      (to Door Side Airbag Sensor LH)
      *b

      Front view of wire harness connector

      (to Side Airbag Sensor Assembly LH)

      Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.

    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
      H27-2 (BDL+) - Body ground Power switch on (IG) Below 1 V
      H27-1 (BDL-) - 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 1 (BDL+) and 2 (BDL-) 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
      H27-2 (BDL+) - H27-1 (BDL-) 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
      H27-2 (BDL+) - H27-1 (BDL-) Always 1 MΩ or higher
      H27-2 (BDL+) - Body ground Always 1 MΩ or higher
      H27-1 (BDL-) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

  13. Click here

    CHECK DTC


    1. B004UF3C15
      *1 Door Side Airbag Sensor LH
      *2 Side Airbag Sensor Assembly LH

      Connect the connectors to the door side airbag sensor LH and side airbag sensor assembly LH.

    2. Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.

    3. Turn the power switch on (IG), and wait for at least 60 seconds.

    4. Clear the DTCs.

      Click here


      1. Body Electrical > SRS Airbag > Clear DTCs


    5. Turn the power switch off.

    6. Turn the power switch on (IG), and wait for at least 60 seconds.

    7. Check for DTCs.

      Click here


      1. Body Electrical > SRS Airbag > Trouble Codes


      Result
      Proceed to
      DTC B1638 is output
      DTC B1638 is not output
      Tip:

      Codes other than DTC B1638 may be output at this time, but they are not related to this check.


    • DTC B1638 is output

      REPLACE AIRBAG ECU ASSEMBLYClick here

    • DTC B1638 is not output

      USE SIMULATION METHOD TO CHECKClick here

  14. Click here

    CHECK FLOOR WIRE


    1. B004TNEC05
      *1 Door Side Airbag Sensor LH
      *2 Side Airbag Sensor Assembly LH
      *3 Front Door Wire LH
      *4 Floor Wire
      *5 Service Wire
      *a

      Front view of wire harness connector

      (to Front Door Wire LH)
      *b

      Front view of wire harness connector

      (to Side Airbag Sensor Assembly LH)

      Disconnect the floor wire connector from the front door wire LH.

    2. Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.

    3. Turn the power switch on (IG).

    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      L 2-10 (BDL+) - Body ground Power switch on (IG) Below 1 V
      L 2-20 (BDL-) - Body ground Power switch on (IG) Below 1 V

    5. Turn the power switch off.

    6. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.

    7. Using a service wire, connect terminals 1 (BDL+) and 2 (BDL-) of connector B.

      Note:

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L 2-10 (BDL+) - L 2-20 (BDL-) Always Below 1 Ω

    9. Disconnect the service wire from connector B.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L 2-10 (BDL+) - L 2-20 (BDL-) Always 1 MΩ or higher
      L 2-10 (BDL+) - Body ground Always 1 MΩ or higher
      L 2-20 (BDL-) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    • OK

      REPLACE FRONT DOOR WIRE LH

    • NG

      REPLACE FLOOR WIRE