RX400h · Service Manual RESTRAINTS

B1148/36

Diagnostic trouble codes

DESCRIPTION

The front airbag sensor RH circuit consists of the diagnosis circuit and the frontal deceleration sensor, etc. If the center airbag sensor assembly receives signals from the frontal deceleration sensor, it judges whether or not the SRS should be activated.
DTC B1148/36 is recorded when a malfunction is detected in the front airbag sensor RH circuit.
DTC No.
 DTC Detecting Condition
 Trouble Area
B1148/36
  1. Open circuit in +SR wire harness or -SR wire harness of front airbag sensor RH circuit
  2. Front airbag sensor RH sensor malfunction
  3. Center airbag sensor assembly malfunction
  1. Front airbag sensor RH
  2. Center airbag sensor assembly
  3. Engine room main wire
  4. Instrument panel wire

WIRING DIAGRAM

H002750E17

INSPECTION PROCEDURE


1. CHECK FRONT AIRBAG SENSOR RH

  1. C110454E01
    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 B1148/36 is not output.

    HINT:
    Codes other than code B1148/36 may be output at this time, but they are not related to this check.



 NG
Go to step 2
OK

USE SIMULATION METHOD TO CHECK

2. CHECK CONNECTION OF 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. Check that the connectors are properly connected to the center airbag sensor assembly and the front airbag sensor RH.

    OK:
    The connectors are connected.



 NG
CONNECT CONNECTORS, THEN GO TO STEP 1
OK


3. CHECK FRONT AIRBAG SENSOR RH CIRCUIT (OPEN)

  1. C110455E03
    Disconnect the connectors from the center airbag sensor assembly and the front airbag sensor RH.

  1. Using a service wire, connect A24-9 (+SR) and A24-20 (-SR) of connector "B".

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

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

    Resistance:
    Tester connection
    		 Condition
    		 Specified condition
    A7-2 (+SR) -
    A7-1 (-SR)
    		 Always
    		 Below 1 Ω



NG:
Go to step 5
OK


4. CHECK FRONT AIRBAG SENSOR RH

  1. C110456E02
    Disconnect the service wire from connector "B".

  1. Connect the connector to the center airbag sensor assembly.

  1. Interchange the front airbag sensor RH with LH, and connect the connectors to them.

  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).

    Result:
    Proceed To
    		 Display (DTC Output)
    NG:A
    		 DTC B1148/36 is output.
    NG:B
    		 DTC B1149/37 is output.
    OK
    		 DTC B1148/36 and B1149/37 are not output.



NG:A
REPLACE CENTER AIRBAG SENSOR ASSEMBLY

NG:B
REPLACE FRONT AIRBAG SENSOR RH
OK

USE SIMULATION METHOD TO CHECK

5. CHECK INSTRUMENT PANEL WIRE (OPEN)

  1. C110457E02
    Disconnect the instrument panel wire connector from the engine room main wire.

    HINT:
    The service wire has already been inserted into connector "B".

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

    Resistance:
    Tester connection
    		 Condition
    		 Specified condition
    IM1-1 (+SR) -
    IM1-2 (-SR)
    		 Always
    		 Below 1 Ω



NG
REPAIR OR REPLACE INSTRUMENT PANEL WIRE
OK

REPAIR OR REPLACE ENGINE ROOM MAIN WIRE


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