RX400h · Service Manual RESTRAINTS

B1651/49

Diagnostic trouble codes

DESCRIPTION

The driver side knee airbag squib circuit consists of the center airbag sensor assembly and the driver side knee airbag assembly.
The circuit instructs the SRS to deploy when deployment conditions are met.
DTC B1651/49 is recorded when an open circuit is detected in the driver side knee airbag squib circuit.
DTC No.
 DTC Detecting Condition
 Trouble Area
B1651/49
  1. Open circuit in DK+ wire harness or DK- wire harness of driver side knee airbag squib
  2. Driver side knee airbag squib malfunction
  3. Center airbag sensor assembly malfunction
  1. Driver side knee airbag assembly (Driver side knee airbag squib)
  2. Center airbag sensor assembly
  3. Floor wire No.2 (LHD)
  4. Floor wire (RHD)

WIRING DIAGRAM

Click here.

INSPECTION PROCEDURE

Result:
A:
LHD
B:
RHD


1. CHECK VEHICLE STEERING POSITION


B
Go to step 6
A


2. CHECK DRIVER SIDE KNEE AIRBAG ASSEMBLY (DRIVER SIDE KNEE AIRBAG SQUIB)

  1. C111702E05
    Turn the ignition switch to the LOCK position.

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

  1. Disconnect the connectors from the driver side knee airbag assembly.

  1. Connect the white wire side of SST (resistance 2.1 Ω) to the floor wire No.2.

    CAUTION:
    Never connect a tester to the driver side knee airbag assembly (Driver side knee airbag squib) for measurement, as this may lead to a serious injury due to airbag deployment.

    NOTICE:
    Do not forcibly insert the SST into the terminals of the connector when connecting.
    Insert the SST straight into the terminals of the connector.

SST
09843-18060  

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

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

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

  1. Turn the ignition switch to the LOCK position.

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

  1. Check the DTCs (Click here).

    OK:
    DTC B1651/49 is not output.

    HINT:
    Codes other than DTC B1651/49 may be output at this time, but they are not related to this check.



 NG
Go to step 3
OK

REPLACE DRIVER SIDE KNEE AIRBAG ASSEMBLY

3. CHECK CONNECTORS

  1. Turn the ignition switch to the LOCK position.

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

  1. Disconnect the SST (resistance 2.1 Ω) from the floor wire No.2.

  1. Check that the floor wire No.2 connector (on the driver side knee airbag assembly side) is not damaged.

    OK:
    The lock button is not disengaged, and the claw of the lock is not deformed or damaged.



 NG
REPAIR OR REPLACE FLOOR WIRE NO.2
OK


4. CHECK FLOOR WIRE NO.2 (DRIVER SIDE KNEE AIRBAG SQUIB CIRCUIT)

  1. C111703E03
    Disconnect the connector from the center airbag sensor assembly.

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

    Resistance:
    Tester connection
    		 Condition
    		 Specified condition
    K8-1 (DK+) -
    K8-2 (DK-)
    		 Always
    		 Below 1 Ω



NG
REPAIR OR REPLACE FLOOR WIRE NO.2
OK


5. CHECK CENTER AIRBAG SENSOR ASSEMBLY

  1. C111704E01
    Connect the connectors to the driver side knee airbag assembly and the center airbag sensor assembly.

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

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

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

  1. Turn the ignition switch to the LOCK position.

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

  1. Check the DTCs (Click here).

    OK:
    DTC B1651/49 is not output.

    HINT:
    Codes other than DTC B1651/49 may be output at this time, but they are not related to this check.



 NG
REPLACE CENTER AIRBAG SENSOR ASSEMBLY
OK

USE SIMULATION METHOD TO CHECK

6. CHECK DRIVER SIDE KNEE AIRBAG ASSEMBLY (DRIVER SIDE KNEE AIRBAG SQUIB)

  1. C114783E01
    Turn the ignition switch to the LOCK position.

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

  1. Disconnect the connectors from the driver side knee airbag assembly.

  1. Connect the white wire side of SST (resistance 2.1 Ω) to the floor wire.

    CAUTION:
    Never connect a tester to the driver side knee airbag assembly (Driver side knee airbag squib) for measurement, as this may lead to a serious injury due to airbag deployment.

    NOTICE:
    Do not forcibly insert the SST into the terminals of the connector when connecting.
    Insert the SST straight into the terminals of the connector.

SST
09843-18060  

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

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

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

  1. Turn the ignition switch to the LOCK position.

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

  1. Check the DTCs (Click here).

    OK:
    DTC B1651/49 is not output.

    HINT:
    Codes other than DTC B1651/49 may be output at this time, but they are not related to this check.



 NG
Go to step 7
OK

REPLACE DRIVER SIDE KNEE AIRBAG ASSEMBLY

7. CHECK CONNECTORS

  1. Turn the ignition switch to the LOCK position.

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

  1. Disconnect the SST (resistance 2.1 Ω) from the floor wire.

  1. Check that the floor wire connector (on the driver side knee airbag assembly side) is not damaged.

    OK:
    The lock button is not disengaged, and the claw of the lock is not deformed or damaged.



 NG
REPAIR OR REPLACE FLOOR WIRE
OK


8. CHECK FLOOR WIRE (DRIVER SIDE KNEE AIRBAG SQUIB CIRCUIT)

  1. C114784E01
    Disconnect the connector from the center airbag sensor assembly.

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

    Resistance:
    Tester connection
    		 Condition
    		 Specified condition
    K8-1 (DK+) -
    K8-2 (DK-)
    		 Always
    		 Below 1 Ω



NG
REPAIR OR REPLACE FLOOR WIRE
OK


9. CHECK CENTER AIRBAG SENSOR ASSEMBLY

  1. C114785E01
    Connect the connectors to the driver side knee airbag assembly and the center airbag sensor assembly.

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

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

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

  1. Turn the ignition switch to the LOCK position.

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

  1. Check the DTCs (Click here).

    OK:
    DTC B1651/49 is not output.

    HINT:
    Codes other than DTC B1651/49 may be output at this time, but they are not related to this check.



 NG
REPLACE CENTER AIRBAG SENSOR ASSEMBLY
OK

USE SIMULATION METHOD TO CHECK


← B1650/49B1652/49 →