Lexus IS250 IS220d GSE20 ALE20 - SUPPLEMENTAL RESTRAINT SYSTEM

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

The driver side squib circuit consists of the center airbag sensor assembly, the spiral cable and the steering pad.
The circuit instructs the SRS to deploy when deployment conditions are met.
These DTCs are recorded when a malfunction is detected in the driver side squib circuit.
DTC No.DTC Detecting ConditionTrouble Area
B1800/51
The center airbag sensor assembly receives a line short circuit signal 5 times in the driver side squib circuit during primary check.
Driver side squib malfunction
Spiral cable malfunction
Center airbag sensor assembly malfunction
Instrument panel wire
Spiral cable
Steering pad (Driver side squib)
Center airbag sensor assembly
B1801/51
The center airbag sensor assembly receives an open circuit signal in the driver side squib circuit for 2 seconds.
Driver side squib malfunction
Spiral cable malfunction
Center airbag sensor assembly malfunction
Instrument panel wire
Spiral cable
Steering pad (Driver side squib)
Center airbag sensor assembly
B1802/51
The center airbag sensor assembly receives a short circuit to ground signal in the driver side squib circuit for 0.5 seconds.
Driver side squib malfunction
Spiral cable malfunction
Center airbag sensor assembly malfunction
Instrument panel wire
Spiral cable
Steering pad (Driver side squib)
Center airbag sensor assembly
B1803/51
The center airbag sensor assembly receives a short circuit to B+ signal in the driver side squib circuit for 0.5 seconds.
Driver side squib malfunction
Spiral cable malfunction
Center airbag sensor assembly malfunction
Instrument panel wire
Spiral cable
Steering pad (Driver side squib)
Center airbag sensor assembly

WIRING DIAGRAM

Dtc B1800/51 Short In Driver Side Squib Circuit. SUPPLEMENTAL RESTRAINT SYSTEM. Lexus IS250 IS220d GSE20 ALE20

INSPECTION PROCEDURE

  • HINT:
Perform the simulation method by selecting the "check mode" (signal check) with the intelligent tester .
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 .
1.CHECK STEERING PAD (DRIVER SIDE SQUIB)
Dtc B1800/51 Short In Driver Side Squib Circuit. SUPPLEMENTAL RESTRAINT SYSTEM. Lexus IS250 IS220d GSE20 ALE20

Turn the engine switch off.

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

Disconnect the connectors from the steering pad.

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 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 straight the SST into the terminals of the connector.
  • SST
  • 09843-18060

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

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

Clear the DTCs stored in the memory .

Turn the engine switch off.

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

Check for DTCs .

  • 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
Go to step 5
OK
4.CHECK CENTER AIRBAG SENSOR ASSEMBLY
Dtc B1800/51 Short In Driver Side Squib Circuit. SUPPLEMENTAL RESTRAINT SYSTEM. Lexus IS250 IS220d GSE20 ALE20

Connect the connectors to the steering pad and the center airbag sensor assembly.

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

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

Clear the DTCs stored in the memory .

Turn the engine switch off.

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

Check for DTCs .

  • 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
Dtc B1800/51 Short In Driver Side Squib Circuit. SUPPLEMENTAL RESTRAINT SYSTEM. Lexus IS250 IS220d GSE20 ALE20

Restore the released activation prevention mechanism of connector "B" to the original condition.

Disconnect the instrument panel wire connector from the spiral cable.

Check for a short to B+ in the circuit.


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

Turn the engine switch on (IG).

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

  • Standard voltage:
  • Tester connectionConditionSpecified condition
    J25-1 (D+) - Body groundEngine switch on (IG)Below 1 V
    J25-2 (D-) - Body groundEngine switch on (IG)Below 1 V

Check for an open in the circuit.


Turn the engine switch off.

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

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

  • Standard resistance:
  • Tester connectionConditionSpecified condition
    J25-1 (D+) - J25-2 (D-)AlwaysBelow 1 Ω

Check for a short to ground in the circuit.


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

  • Standard resistance:
  • Tester connectionConditionSpecified condition
    J25-1 (D+) - Body groundAlways1 MΩ or higher
    J25-2 (D-) - Body groundAlways1 MΩ or higher

Check for a short in the circuit.


Release the activation prevention mechanism built into connector "B" .

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

  • Standard resistance:
  • Tester connectionConditionSpecified condition
    J25-1 (D+) - J25-2 (D-)Always1 MΩ or higher
NG
REPAIR OR REPLACE INSTRUMENT PANEL WIRE
OK
6.CHECK SPIRAL CABLE
Dtc B1800/51 Short In Driver Side Squib Circuit. SUPPLEMENTAL RESTRAINT SYSTEM. Lexus IS250 IS220d GSE20 ALE20

Check for a short to B+ in the circuit.


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

Turn the engine switch on (IG).

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

  • Standard voltage:
  • Tester connectionConditionSpecified condition
    D+ - Body groundEngine switch on (IG)Below 1 V
    D- - Body groundEngine switch on (IG)Below 1 V

Check for an open in the circuit.


Turn the engine switch off.

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

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

  • Standard resistance:
  • Tester connectionConditionSpecified condition
    D+ - D-AlwaysBelow 1 Ω

Check for a short to ground in the circuit.


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

  • Standard resistance:
  • Tester connectionConditionSpecified condition
    D+ - Body groundAlways1 MΩ or higher
    D- - Body groundAlways1 MΩ or higher

Check for a short in the circuit.


Release the activation prevention mechanism built into connector "D" .

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

  • Standard resistance:
  • Tester connectionConditionSpecified condition
    D+ - D-Always1 MΩ or higher
NG
REPLACE SPIRAL CABLE
OK
USE SIMULATION METHOD TO CHECK
LEXUS IS250, IS220d / GSE20 ALE20
SUPPLEMENTAL RESTRAINT SYSTEM
Lexus IS250 IS220d GSE20 ALE20
AIRBAG SYSTEM