Dtc B1800/51 Short In Driver Side Squib Circuit

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

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK STEERING PAD (DRIVER SIDE SQUIB)

CHECK CONNECTOR

CHECK DRIVER SIDE SQUIB CIRCUIT

CHECK CENTER AIRBAG SENSOR ASSEMBLY

CHECK INSTRUMENT PANEL WIRE

CHECK SPIRAL CABLE

DTC B1800/51 Short in Driver Side Squib Circuit

DTC B1801/51 Open in Driver Side Squib Circuit

DTC B1802/51 Short to GND in Driver Side Squib Circuit

DTC B1803/51 Short to B+ in Driver Side Squib Circuit


DESCRIPTION

  1. The driver side squib circuit consists of the center airbag sensor assembly, the spiral cable and the steering pad.
  2. The circuit instructs the SRS to deploy when deployment conditions are met.
  3. These DTCs are recorded when a malfunction is detected in the driver side squib circuit.

DTC No.
DTC Detecting Condition
Trouble Area
B1800/51
  1. The center airbag sensor assembly receives a line short circuit signal 5 times in the driver side squib circuit during primary check.
  2. Driver side squib malfunction
  3. Spiral cable malfunction
  4. Center airbag sensor assembly malfunction
  1. Instrument panel wire
  2. Spiral cable
  3. Steering pad (Driver side squib)
  4. Center airbag sensor assembly
B1801/51
  1. The center airbag sensor assembly receives an open circuit signal in the driver side squib circuit for 2 seconds.
  2. Driver side squib malfunction
  3. Spiral cable malfunction
  4. Center airbag sensor assembly malfunction
  1. Instrument panel wire
  2. Spiral cable
  3. Steering pad (Driver side squib)
  4. Center airbag sensor assembly
B1802/51
  1. The center airbag sensor assembly receives a short circuit to ground signal in the driver side squib circuit for 0.5 seconds.
  2. Driver side squib malfunction
  3. Spiral cable malfunction
  4. Center airbag sensor assembly malfunction
  1. Instrument panel wire
  2. Spiral cable
  3. Steering pad (Driver side squib)
  4. Center airbag sensor assembly
B1803/51
  1. The center airbag sensor assembly receives a short circuit to B+ signal in the driver side squib circuit for 0.5 seconds.
  2. Driver side squib malfunction
  3. Spiral cable malfunction
  4. Center airbag sensor assembly malfunction
  1. Instrument panel wire
  2. Spiral cable
  3. Steering pad (Driver side squib)
  4. Center airbag sensor assembly

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System.
Dtc
  B1800/51  Short In Driver Side Squib Circuit


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 STEERING PAD (DRIVER SIDE SQUIB)


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System.
Dtc
  B1800/51  Short In Driver Side Squib Circuit
  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 connectors from the steering pad.

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

    CAUTION:
    Never connect a tester to the steering pad (Driver side squib) for measurement, as the 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.
SST
09843-18060
  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 B1800, B1801, B1802, B1803 or 51 is not output.
    HINT:
    Codes other than DTC B1800, B1801, B1802, B1803 and 51 may be output at this time, but they are not related to this check.


OK
REPLACE STEERING PAD
NG


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 "E".

  1. Check that the spiral cable connectors (on the steering pad side) are not damaged.

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


NG
REPLACE SPIRAL CABLE
OK


3.CHECK DRIVER SIDE SQUIB CIRCUIT


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System.
Dtc
  B1800/51  Short In Driver Side Squib Circuit
  1. Disconnect the connectors from the center airbag sensor assembly.

  1. Check the 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.

      Voltage:
      Tester connection
      Condition
      Specified condition
      D+ - Body ground
      Engine switch on (IG)
      Below 1 V
      D- - Body ground
      Engine switch on (IG)
      Below 1 V
  1. Check the 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.

      Resistance:
      Tester connection
      Condition
      Specified condition
      D+ - D-
      Always
      Below 1 Ω
  1. Check the short to ground in the circuit.

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

      Resistance:
      Tester connection
      Condition
      Specified condition
      D+ - Body ground
      Always
      1 MΩ or higher
      D- - Body ground
      Always
      1 MΩ or higher
  1. Check for 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.

      Resistance:
      Tester connection
      Condition
      Specified condition
      D+ - D-
      Always
      1 MΩ or higher


NG
Go to step 5
OK


4.CHECK CENTER AIRBAG SENSOR ASSEMBLY


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System.
Dtc
  B1800/51  Short In Driver Side Squib Circuit
  1. Connect the connectors to the steering pad 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 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 B1800, B1801, B1802, B1803 or 51 is not output.
    HINT:
    Codes other than DTC B1800, B1801, B1802, B1803 and 51 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

5.CHECK INSTRUMENT PANEL WIRE


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System.
Dtc
  B1800/51  Short In Driver Side Squib Circuit
  1. Restore the released activation prevention mechanism of connector "B" to the original condition.

  1. Disconnect the instrument panel wire connector from the spiral cable.

  1. Check the 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.

      Voltage:
      Tester connection
      Condition
      Specified condition
      L21-1 (D+) -
      Body ground
      Engine switch on (IG)
      Below 1 V
      L21-2 (D-) -
      Body ground
      Engine switch on (IG)
      Below 1 V
  1. Check the 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.

      Resistance:
      Tester connection
      Condition
      Specified condition
      L21-1 (D+) - L21-2 (D-)
      Always
      Below 1 Ω
  1. Check the short to ground in the circuit.

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

      Resistance:
      Tester connection
      Condition
      Specified condition
      L21-1 (D+) -
      Body ground
      Always
      1 MΩ or higher
      L21-2 (D-) -
      Body ground
      Always
      1 MΩ or higher
  1. Check the 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.

      Resistance:
      Tester connection
      Condition
      Specified condition
      L21-1 (D+) - L21-2 (D-)
      Always
      1 MΩ or higher


NG
REPAIR OR REPLACE INSTRUMENT PANEL WIRE
OK


6.CHECK SPIRAL CABLE


    Lexus Gs430, Gs300. Uzs190 Grs190.Supplemental Restraint System.Airbag System.
Dtc
  B1800/51  Short In Driver Side Squib Circuit
  1. Check the 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.

      Voltage:
      Tester connection
      Condition
      Specified condition
      D+ - Body ground
      Engine switch on (IG)
      Below 1 V
      D- - Body ground
      Engine switch on (IG)
      Below 1 V
  1. Check the 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.

      Resistance:
      Tester connection
      Condition
      Specified condition
      D+ - D-
      Always
      Below 1 Ω
  1. Check the short to ground in the circuit.

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

      Resistance:
      Tester connection
      Condition
      Specified condition
      D+ - Body ground
      Always
      1 MΩ or higher
      D- - Body ground
      Always
      1 MΩ or higher
  1. Check the short in the circuit.

    1. Release the activation prevention mechanism built into connector "D" (Click here).

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

      Resistance:
      Tester connection
      Condition
      Specified condition
      D+ - D-
      Always
      1 MΩ or higher


NG
REPLACE SPIRAL CABLE
OK

USE SIMULATION METHOD TO CHECK