AIRBAG SYSTEM, Diagnostic DTC:B1651/33

DTC Code DTC Name
B1651/33 Manual Cut off Switch Trouble

DESCRIPTION

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

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

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

DTC B1651/33 is stored when a malfunction is detected in the airbag cut off switch circuit.

DTC No. DTC Detecting Condition Trouble Area
B1651/33

  • 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 cylinder sub-assembly malfunction

  • Airbag ECU assembly malfunction

  • Instrument panel wire

  • Airbag cut off switch cylinder sub-assembly

  • Airbag ECU assembly

WIRING DIAGRAM

B005YE2E25
*a Airbag Cut Off Switch Cylinder Sub-assembly
*b Airbag ECU Assembly

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 Click here.

Tech Tips

Terminals L16-11 (MSW+) and L16-12 (MSW-) of the airbag ECU assembly in this circuit have an activation prevention mechanism.

This mechanism can be used to check for an open circuit in the wire harness. In case of other checks (check for short, short to ground or short to B+), this mechanism should be released.

PROCEDURE


  1. CHECK CONNECTORS


    1. Turn the power switch off.

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

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary 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 cylinder sub-assembly.

      OK
      The connectors are properly connected.

      Tech Tips

      If the connectors are 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 cylinder sub-assembly.

    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. B005ZOPE01
      Text in Illustration
      *1 Airbag Cut Off Switch Cylinder Sub-assembly
      *2 Airbag ECU Assembly
      *3 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Airbag Cut Off Switch Cylinder Sub-assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L148-2 (PMC+) - L148-1 (PMC-) Always Below 1 Ω

    NG

    REPLACE INSTRUMENT PANEL WIRE

    OK

  3. CHECK INSTRUMENT PANEL WIRE (SHORT)


    1. B005ZOPE01
      Text in Illustration
      *1 Airbag Cut Off Switch Cylinder Sub-assembly
      *2 Airbag ECU Assembly
      *3 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Airbag Cut Off Switch Cylinder Sub-assembly)

      Release the activation prevention mechanism built into connector B Click here.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L148-2 (PMC+) - L148-1 (PMC-) Always 1 MΩ or higher

    3. Restore the released activation prevention mechanism of connector B to the original condition.


    NG

    REPLACE INSTRUMENT PANEL WIRE

    OK

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


    1. B005ZOPE01
      Text in Illustration
      *1 Airbag Cut Off Switch Cylinder Sub-assembly
      *2 Airbag ECU Assembly
      *3 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Airbag Cut Off Switch Cylinder Sub-assembly)

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

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      L148-2 (PMC+) - Body ground Power switch on (IG) Below 1 V
      L148-1 (PMC-) - Body ground Power switch on (IG) Below 1 V

    NG

    REPLACE INSTRUMENT PANEL WIRE

    OK

  5. CHECK INSTRUMENT PANEL WIRE (SHORT TO GROUND)


    1. B005ZOPE01
      Text in Illustration
      *1 Airbag Cut Off Switch Cylinder Sub-assembly
      *2 Airbag ECU Assembly
      *3 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Airbag Cut Off Switch Cylinder Sub-assembly)

      Turn the power switch off.

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

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary 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
      L148-2 (PMC+) - Body ground Always 1 MΩ or higher
      L148-1 (PMC-) - Body ground Always 1 MΩ or higher

    NG

    REPLACE INSTRUMENT PANEL WIRE

    OK

  6. CHECK AIRBAG CUT OFF SWITCH CYLINDER SUB-ASSEMBLY


    1. B005XG9E01
      Text in Illustration
      *a

      Component without harness connected

      (Airbag Cut Off Switch Cylinder Sub-assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L148-2 (PMC+) - L148-1 (PMC-) Cut off switch is ON 360 to 440 Ω
      L148-2 (PMC+) - L148-1 (PMC-) Cut off switch is OFF 90 to 110 Ω

    NG

    REPLACE AIRBAG CUT OFF SWITCH CYLINDER SUB-ASSEMBLY Click here

    OK

  7. CHECK AIRBAG ECU ASSEMBLY


    1. B005ZEUE03
      Text in Illustration
      *1 Airbag Cut Off Switch Cylinder Sub-assembly
      *2 Airbag ECU Assembly

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

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

    3. Clear the DTCs stored in memory Click here.

    4. Turn the power switch off.

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

    6. Check for DTCs Click here.

      OK
      DTC B1651/33 is not output.

      Tech Tips

      Codes other than DTC B1651/33 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