Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

Restraints. Lexus Gs430, Gs300. Uzs190 Grs190
Supplemental Restraint System. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK FRONT AIRBAG SENSOR LH CIRCUIT (SHORT TO B+)

CHECK FRONT AIRBAG SENSOR LH CIRCUIT (SHORT)

CHECK FRONT AIRBAG SENSOR LH CIRCUIT (SHORT TO GROUND)

CHECK FRONT AIRBAG SENSOR RH CIRCUIT (SHORT TO B+)

CHECK FRONT AIRBAG SENSOR RH CIRCUIT (SHORT)

CHECK FRONT AIRBAG SENSOR RH CIRCUIT (SHORT TO GROUND)

CHECK CENTER AIRBAG SENSOR ASSEMBLY

CHECK ENGINE ROOM MAIN WIRE (SHORT TO B+)

CHECK ENGINE ROOM MAIN WIRE (SHORT)

CHECK ENGINE ROOM MAIN WIRE (SHORT TO GROUND)

CHECK ENGINE ROOM MAIN WIRE (SHORT TO B+)

CHECK ENGINE ROOM MAIN WIRE (SHORT)

CHECK ENGINE ROOM MAIN WIRE (SHORT TO GROUND)

DTC B1000/31 Center Airbag Sensor Assembly Malfunction


DESCRIPTION

The center airbag sensor assembly consists of the airbag sensor, the safing sensor, the drive circuit, the diagnosis circuit, the ignition control, etc.
If the center airbag sensor assembly receives signals from the airbag sensor, it determines whether or not the SRS should be activated.
DTC B1000/31 is recorded when a malfunction is detected in the center airbag sensor assembly.

DTC No.
DTC Detecting Condition
Trouble Area
B1000/31
  1. The center airbag sensor assembly receives a line short circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the front airbag sensor LH circuit for 2 seconds.
  2. The center airbag sensor assembly receives a line short circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the front airbag sensor RH circuit for 2 seconds.
  3. Center airbag sensor assembly malfunction
  1. Instrument panel wire
  2. Engine room main wire
  3. Center airbag sensor assembly
HINT:
When a malfunction code is displayed simultaneously with B1000/31, repair the malfunction indicated by this code (except B1000/31) first.

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction


INSPECTION PROCEDURE

1.CHECK FRONT AIRBAG SENSOR LH CIRCUIT (SHORT TO B+)


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

  1. Disconnect the connectors from the center airbag sensor assembly and the front airbag sensor LH.

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

  1. Turn the engine switch on (IG).

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

    Voltage:
    Tester connection
    		Condition
    		Specified condition
    A1-2 (+SL) -
    Body ground
    		Engine switch on (IG)
    		Below 1 V
    A1-1 (-SL) -
    Body ground
    		Engine switch on (IG)
    		Below 1 V


NG
Go to step 8
OK


2.CHECK FRONT AIRBAG SENSOR LH CIRCUIT (SHORT)


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

  1. Turn the engine switch off.

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

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

    Resistance:
    Tester connection
    		Condition
    		Specified condition
    A1-2 (+SL) -
    A1-1 (-SL)
    		Always
    		1 MΩ or higher


NG
Go to step 9
OK


3.CHECK FRONT AIRBAG SENSOR LH CIRCUIT (SHORT TO GROUND)


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

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

    Resistance:
    Tester connection
    		Condition
    		Specified condition
    A1-2 (+SL) -
    Body ground
    		Always
    		1 MΩ or higher
    A1-1 (-SL) -
    Body ground
    		Always
    		1 MΩ or higher


NG
Go to step 10
OK


4.CHECK FRONT AIRBAG SENSOR RH CIRCUIT (SHORT TO B+)


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

  1. Disconnect the connector from the front airbag sensor RH.

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

  1. Turn the engine switch on (IG).

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

    Voltage:
    Tester connection
    		Condition
    		Specified condition
    A25-2 (+SR) -
    Body ground
    		Engine switch on (IG)
    		Below 1 V
    A25-1 (+SR) -
    Body ground
    		Engine switch on (IG)
    		Below 1 V


NG
Go to step 11
OK


5.CHECK FRONT AIRBAG SENSOR RH CIRCUIT (SHORT)


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

  1. Turn the engine switch off.

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

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

    Resistance:
    Tester connection
    		Condition
    		Specified condition
    A25-2 (+SR) -
    A25-1 (-SR)
    		Always
    		1 MΩ or higher


NG
Go to step 12
OK


6.CHECK FRONT AIRBAG SENSOR RH CIRCUIT (SHORT TO GROUND)


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

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

    Resistance:
    Tester connection
    		Condition
    		Specified condition
    A25-2 (+SR) -
    Body ground
    		Always
    		1 MΩ or higher
    A25-1 (-SR) -
    Body ground
    		Always
    		1 MΩ or higher


NG
Go to step 13
OK


7.CHECK CENTER AIRBAG SENSOR ASSEMBLY


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

  1. Connect the connectors to the center airbag sensor assembly, front airbag sensor LH and RH.

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

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

  1. Clear the DTCs stored in memory (Click here).

  1. Turn the engine switch off.

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

  1. Check the DTCs (Click here).

    OK:
    DTC B1000/31 is not output.


NG
REPLACE CENTER AIRBAG SENSOR ASSEMBLY
OK

USE SIMULATION METHOD TO CHECK

8.CHECK ENGINE ROOM MAIN WIRE (SHORT TO B+)


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

  1. Turn the engine switch off.

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

  1. Disconnect the engine room main wire connector from the instrument panel wire.

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

  1. Turn the engine switch on (IG).

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

    Voltage:
    Tester connection
    		Condition
    		Specified condition
    A1-2 (+SL) -
    Body ground
    		Engine switch on (IG)
    		Below 1 V
    A1-1 (-SL) -
    Body ground
    		Engine switch on (IG)
    		Below 1 V


NG
REPAIR OR REPLACE ENGINE ROOM MAIN WIRE
OK

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

9.CHECK ENGINE ROOM MAIN WIRE (SHORT)


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

  1. Disconnect the engine room main wire connector from the instrument panel wire.

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

    Resistance:
    Tester connection
    		Condition
    		Specified condition
    A1-2 (+SL) -
    A1-1 (-SL)
    		Always
    		1 MΩ or higher


NG
REPAIR OR REPLACE ENGINE ROOM MAIN WIRE
OK

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

10.CHECK ENGINE ROOM MAIN WIRE (SHORT TO GROUND)


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

  1. Disconnect the engine room main wire connector from the instrument panel wire.

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

    Resistance:
    Tester connection
    		Condition
    		Specified condition
    A1-2 (+SL) -
    Body ground
    		Always
    		1 MΩ or higher
    A1-1 (-SL) -
    Body ground
    		Always
    		1 MΩ or higher


NG
REPAIR OR REPLACE ENGINE ROOM MAIN WIRE
OK

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

11.CHECK ENGINE ROOM MAIN WIRE (SHORT TO B+)


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

  1. Turn the engine switch off.

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

  1. Disconnect the engine room main wire connector from the instrument panel wire.

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

  1. Turn the engine switch on (IG).

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

    Voltage:
    Tester connection
    		Condition
    		Specified condition
    A25-2 (+SR) -
    Body ground
    		Engine switch on (IG)
    		Below 1 V
    A25-1 (-SR) -
    Body ground
    		Engine switch on (IG)
    		Below 1 V


NG
REPAIR OR REPLACE ENGINE ROOM MAIN WIRE
OK

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

12.CHECK ENGINE ROOM MAIN WIRE (SHORT)


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

  1. Disconnect the engine room main wire connector from the instrument panel wire.

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

    Resistance:
    Tester connection
    		Condition
    		Specified condition
    A25-2 (+SR) -
    A25-1 (-SR)
    		Always
    		1 MΩ or higher


NG
REPAIR OR REPLACE ENGINE ROOM MAIN WIRE
OK

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

13.CHECK ENGINE ROOM MAIN WIRE (SHORT TO GROUND)


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System. Dtc B1000/31 Center Airbag Sensor Assembly Malfunction

  1. Disconnect the engine room main wire connector from the instrument panel wire.

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

    Resistance:
    Tester connection
    		Condition
    		Specified condition
    A25-2 (+SR) -
    Body ground
    		Always
    		1 MΩ or higher
    A25-1 (-SR) -
    Body ground
    		Always
    		1 MΩ or higher


NG
REPAIR OR REPLACE ENGINE ROOM MAIN WIRE
OK

REPAIR OR REPLACE INSTRUMENT PANEL WIRE