Lexus IS250 · Service Manual RESTRAINTS

B1835/58

Diagnostic trouble codes

DESCRIPTION

The front passenger side curtain shield squib circuit consists of the center airbag sensor assembly and the curtain shield airbag assembly (front passenger side).
The circuit instructs the SRS to deploy when deployment conditions are met.
These DTCs are recorded when a malfunction is detected in the front passenger side curtain shield squib circuit.
DTC No.
 DTC Detection Condition
 Trouble Area
B1835/58
  1. The center airbag sensor assembly receives a line short circuit signal 5 times in the front passenger side curtain shield squib circuit during primary check.
  2. Front passenger side curtain shield squib malfunction
  3. Center airbag sensor assembly malfunction
  1. Floor wire
  2. Curtain shield airbag assembly (Front passenger side curtain shield squib)
  3. Center airbag sensor assembly
B1836/58
  1. The center airbag sensor assembly receives an open circuit signal in the front passenger side curtain shield squib circuit for 2 seconds.
  2. Front passenger side curtain shield squib malfunction
  3. Center airbag sensor assembly malfunction
  1. Floor wire
  2. Curtain shield airbag assembly (Front passenger side curtain shield squib)
  3. Center airbag sensor assembly
B1837/58
  1. The center airbag sensor assembly receives a short circuit to ground signal in the front passenger side curtain shield squib circuit for 0.5 seconds.
  2. Front passenger side curtain shield squib malfunction
  3. Center airbag sensor assembly malfunction
  1. Floor wire
  2. Curtain shield airbag assembly (Front passenger side curtain shield squib)
  3. Center airbag sensor assembly
B1838/58
  1. The center airbag sensor assembly receives a short circuit to B+ signal in the front passenger side curtain shield squib circuit for 0.5 seconds.
  2. Front passenger side curtain shield squib malfunction
  3. Center airbag sensor assembly malfunction
  1. Floor wire
  2. Curtain shield airbag assembly (Front passenger side curtain shield squib)
  3. Center airbag sensor assembly

WIRING DIAGRAM

C124552E17

INSPECTION PROCEDURE

HINT:
  1. Perform the simulation method by selecting the "check mode" (signal check) with the intelligent tester (Click here).
  2. After selecting the "check mode" (signal check), perform the simulation method by wiggling each connector of the airbag system or driving the vehicle on a city or rough road (Click here).


1. CHECK CURTAIN SHIELD AIRBAG ASSEMBLY (FRONT PASSENGER SIDE CURTAIN SHIELD SQUIB)

  1. C114827E04
    Turn the engine switch off.

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

  1. Disconnect the connectors from the curtain shield airbag assembly (front passenger side).

  1. Connect the white wire side of SST (resistance 2.1 Ω) to connector "C".

    CAUTION:
    Never connect a tester to the curtain shield airbag assembly (front passenger side curtain shield squib) for measurement, as this may lead to a serious injury due to airbag deployment.

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

  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 the 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 for DTCs (Click here).

    OK:
    DTC B1835, B1836, B1837, B1838 or 58 is not output.

    HINT:
    Codes other than DTC B1835, B1836, B1837, B1838 and 58 may be output at this time, but they are not related to this check.



 NG
REPLACE CURTAIN SHIELD AIRBAG ASSEMBLY (PASSENGER SIDE)
OK


2. CHECK CONNECTOR

  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 SST from connector "C".

  1. Check that the floor wire connectors (on the curtain shield airbag assembly (front passenger side) side) are not damaged.

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



 NG
REPAIR OR REPLACE FLOOR WIRE
OK


3. CHECK FLOOR WIRE (FRONT PASSENGER SIDE CURTAIN SHIELD SQUIB CIRCUIT)

  1. C111666E07
    Disconnect the connectors from the center airbag sensor assembly.

  1. Check for a short to B+ in the circuit.

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

    2. Turn the engine switch on (IG).

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

      Standard voltage:
      LHD:
      Tester connection
      		 Condition
      		 Specified condition
      P18-1 (ICR+) - Body ground
      		 Engine switch on (IG)
      		 Below 1 V
      P18-2 (ICR-) - Body ground
      		 Engine switch on (IG)
      		 Below 1 V
      RHD:
      Tester connection
      		 Condition
      		 Specified condition
      Q19-1 (ICL+) - Body ground
      		 Engine switch on (IG)
      		 Below 1 V
      Q19-2 (ICL-) - Body ground
      		 Engine switch on (IG)
      		 Below 1 V

  1. Check for an open in the circuit.

    1. Turn the engine switch off.

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

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

      Standard resistance:
      LHD:
      Tester connection
      		 Condition
      		 Specified condition
      P18-1 (ICR+) - P18-2 (ICR-)
      		 Always
      		 Below 1 Ω
      RHD:
      Tester connection
      		 Condition
      		 Specified condition
      Q19-1 (ICL+) - Q19-2 (ICL-)
      		 Always
      		 Below 1 Ω

  1. Check for a short to ground in the circuit.

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

      Standard resistance:
      LHD:
      Tester connection
      		 Condition
      		 Specified condition
      P18-1 (ICR+) - Body ground
      		 Always
      		 1 MΩ or higher
      P18-2 (ICR-) - Body ground
      		 Always
      		 1 MΩ or higher
      RHD:
      Tester connection
      		 Condition
      		 Specified condition
      Q19-1 (ICL+) - Body ground
      		 Always
      		 1 MΩ or higher
      Q19-2 (ICL-) - Body ground
      		 Always
      		 1 MΩ or higher

  1. Check for a short in the circuit.

    1. 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:
      LHD:
      Tester connection
      		 Condition
      		 Specified condition
      P18-1 (ICR+) - P18-2 (ICR-)
      		 Always
      		 1 MΩ or higher
      RHD:
      Tester connection
      		 Condition
      		 Specified condition
      Q19-1 (ICL+) - Q19-2 (ICL-)
      		 Always
      		 1 MΩ or higher



NG
REPAIR OR REPLACE FLOOR WIRE
OK


4. CHECK CENTER AIRBAG SENSOR ASSEMBLY

  1. C114828E01
    Connect the connectors to the curtain shield airbag assembly (front passenger side) 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 engine switch on (IG), and wait for at least 60 seconds.

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

    OK:
    DTC B1835, B1836, B1837, B1838 or 58 is not output.

    HINT:
    Codes other than DTC B1835, B1836, B1837, B1838 and 58 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


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