AIRBAG SYSTEM, Diagnostic DTC:B1651

DTC Code DTC Name
B1651 Manual Cut OFF Switch Trouble

DESCRIPTION

The airbag cut off switch circuit consists of the airbag ECU assembly and airbag cut off switch.

The front passenger airbag can be optionally deactivated via this circuit by turning the airbag cut off switch to the OFF position.

If the front passenger airbag is deactivated, the passenger airbag ON/OFF indicator ("OFF") comes on to inform the passengers.

DTC B1651 is stored when a malfunction is detected in the airbag cut off switch circuit.

DTC No. DTC Detecting Condition Trouble Area
B1651

  • The airbag ECU assembly receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the airbag cut off switch circuit.

  • Airbag cut off switch malfunction

  • Airbag ECU assembly malfunction

  • Instrument panel wire

  • Airbag cut off switch

  • Airbag ECU assembly

WIRING DIAGRAM

A004H8QE01
*a Airbag Cut Off Switch
*b Airbag ECU Assembly

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK CONNECTORS


    1. Turn the ignition switch off.

    2. Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

    3. Check that the connectors are properly connected to the airbag ECU assembly and airbag cut off switch.

      OK
      The connectors are properly connected.

      Tech Tips

      If the connector is not connected securely, reconnect the connector and proceed to the next inspection.

    4. Disconnect the connectors from the airbag ECU assembly and airbag cut off switch.

    5. Check that the terminals of the connectors are not damaged.

      OK
      The terminals are not deformed or damaged.

    6. Check that the short spring for the instrument panel wire connector with the activation prevention mechanism is not deformed or damaged.

      OK
      The short spring is not deformed or damaged.

    NG

    REPLACE INSTRUMENT PANEL WIRE

    OK

  2. CHECK INSTRUMENT PANEL WIRE (OPEN)


    1. Using a service wire, connect terminals 12 (MSW-) and 14 (MSW+) of connector B.

      Note

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

    2. A004KQEE02
      Text in Illustration
      *1 Airbag Cut Off Switch
      *2 Airbag ECU Assembly
      *3 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Airbag ECU Assembly)
      *b

      Front view of wire harness connector

      (to Airbag Cut Off Switch)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D37-1 (MSW-) - D37-2 (MSW+) Always Below 1 Ω

    NG

    REPLACE INSTRUMENT PANEL WIRE

    OK

  3. CHECK INSTRUMENT PANEL WIRE (SHORT)


    1. A004ICGE02
      Text in Illustration
      *1 Airbag Cut Off Switch
      *2 Airbag ECU Assembly
      *3 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Airbag Cut Off Switch)

      Disconnect the service wire from connector B.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D37-2 (MSW+) - D37-1 (MSW-) Always 1 MΩ or higher

    NG

    REPLACE INSTRUMENT PANEL WIRE

    OK

  4. CHECK INSTRUMENT PANEL WIRE (SHORT TO B+)


    1. A004ICGE02
      Text in Illustration
      *1 Airbag Cut Off Switch
      *2 Airbag ECU Assembly
      *3 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Airbag Cut Off Switch)

      Connect the cable to the negative (-) battery terminal.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      D37-1 (MSW-) - Body ground Ignition switch ON Below 1 V
      D37-2 (MSW+) - Body ground Ignition switch ON Below 1 V

    NG

    REPLACE INSTRUMENT PANEL WIRE

    OK

  5. CHECK INSTRUMENT PANEL WIRE (SHORT TO GROUND)


    1. A004ICGE02
      Text in Illustration
      *1 Airbag Cut Off Switch
      *2 Airbag ECU Assembly
      *3 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Airbag Cut Off Switch)

      Turn the ignition switch off.

    2. Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D37-1 (MSW-) - Body ground Always 1 MΩ or higher
      D37-2 (MSW+) - Body ground Always 1 MΩ or higher

    NG

    REPLACE INSTRUMENT PANEL WIRE

    OK

  6. CHECK AIRBAG CUT OFF SWITCH


    1. Inspect the airbag cut off switch Click here.


    NG

    REPLACE AIRBAG CUT OFF SWITCH Click here

    OK

  7. CHECK DTC


    1. A004KGEE02
      Text in Illustration
      *1 Airbag Cut Off Switch
      *2 Airbag ECU Assembly

      Connect the connectors to the airbag ECU assembly and airbag cut off switch.

    2. Connect the cable to the negative (-) battery terminal.

    3. Turn the ignition switch to ON, and wait for at least 60 seconds.

    4. Clear the DTCs stored in the memory Click here.

    5. Turn the ignition switch off.

    6. Turn the ignition switch to ON, and wait for at least 60 seconds.

    7. Check for DTCs Click here.

      OK
      DTC B1651 is not output.

      Tech Tips

      Codes other than DTC B1651 may be output at this time, but they are not related to this check.


    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE AIRBAG ECU ASSEMBLY Click here