Dtc B1865/65 Short In Front Passenger Side Knee Airbag Squib Circuit

Lexus IS250 IS220d GSE20 ALE20 - SUPPLEMENTAL RESTRAINT SYSTEM

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK FRONT PASSENGER SIDE KNEE AIRBAG ASSEMBLY (FRONT PASSENGER SIDE KNEE AIRBAG SQUIB)

CHECK CONNECTOR

CHECK INSTRUMENT PANEL WIRE (FRONT PASSENGER KNEE AIRBAG SQUIB CIRCUIT)

CHECK CENTER AIRBAG SENSOR ASSEMBLY

DTC B1865/65 Short in Front Passenger Side Knee Airbag Squib Circuit

DTC B1866/65 Open in Front Passenger Side Knee Airbag Squib Circuit

DTC B1867/65 Short to GND in Front Passenger Side Knee Airbag Squib Circuit

DTC B1868/65 Short to B+ in Front Passenger Side Knee Airbag Squib Circuit

DESCRIPTION

The front passenger side knee airbag squib circuit consists of the center airbag sensor assembly and the front passenger side knee airbag assembly.


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 knee airbag squib circuit.

DTC No. DTC Detecting ConditionTrouble Area
B1865/65
The center airbag sensor assembly receives a line short circuit signal 5 times in the front passenger side knee airbag squib circuit during primary check.
Front passenger side knee airbag squib malfunction
Center airbag sensor assembly malfunction
Instrument panel wire
Front passenger side knee airbag assembly (Front passenger side knee airbag squib)
Center airbag sensor assembly
B1866/65
The center airbag sensor assembly receives an open circuit signal in the front passenger side knee airbag squib circuit for 2 seconds.
Front passenger side knee airbag squib malfunction
Center airbag sensor assembly malfunction
Instrument panel wire
Front passenger side knee airbag assembly (Front passenger side knee airbag squib)
Center airbag sensor assembly
B1867/65
The center airbag sensor assembly receives a short circuit to ground signal in the front passenger side knee airbag squib circuit for 0.5 seconds.
Front passenger side knee airbag squib malfunction
Center airbag sensor assembly malfunction
Instrument panel wire
Front passenger side knee airbag assembly (Front passenger side knee airbag squib)
Center airbag sensor assembly
B1868/65
The center airbag sensor assembly receives a short circuit to B+ signal in the front passenger side knee airbag squib circuit for 0.5 seconds.
Front passenger side knee airbag squib malfunction
Center airbag sensor assembly malfunction
Instrument panel wire
Front passenger side knee airbag assembly (Front passenger side knee airbag squib)
Center airbag sensor assembly

WIRING DIAGRAM

Dtc B1865/65 Short In Front Passenger Side Knee Airbag 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 FRONT PASSENGER SIDE KNEE AIRBAG ASSEMBLY (FRONT PASSENGER SIDE KNEE AIRBAG SQUIB)
Dtc B1865/65 Short In Front Passenger Side Knee Airbag 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 connector from the front passenger side knee airbag assembly.

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

  • CAUTION:
  • Never connect a tester to the front passenger side knee airbag assembly (front passenger 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 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 B1865, B1866, B1867, B1868 or 65 is not output.
  • HINT:
  • Codes other than DTC B1865, B1866, B1867, B1868 and 65 may be output at this time, but they are not related to this check.
OK
REPLACE FRONT PASSENGER SIDE KNEE AIRBAG ASSEMBLY
NG
2.CHECK CONNECTOR

Turn the engine switch off.

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

Disconnect the SST from connector "C".

Check that the instrument panel wire connector (on the front passenger side knee airbag assembly side) is not damaged.

  • OK:
  • The lock button is not disengaged, or the claw of the lock is not deformed or damaged.
NG
REPAIR OR REPLACE INSTRUMENT PANEL WIRE
OK
3.CHECK INSTRUMENT PANEL WIRE (FRONT PASSENGER KNEE AIRBAG SQUIB CIRCUIT)
Dtc B1865/65 Short In Front Passenger Side Knee Airbag Squib Circuit. SUPPLEMENTAL RESTRAINT SYSTEM. Lexus IS250 IS220d GSE20 ALE20

Disconnect the connectors from the center airbag sensor assembly.

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
    J79-1 (PK+) - Body groundEngine switch on (IG)Below 1 V
    J79-2 (PK-) - 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
    J79-1 (PK+) - J79-2 (PK-)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
    J79-1 (PK+) - Body groundAlways1 MΩ or higher
    J79-2 (PK-) - 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
    J79-1 (PK+) - J79-2 (PK-)Always1 MΩ or higher
NG
REPAIR OR REPLACE INSTRUMENT PANEL WIRE
OK
4.CHECK CENTER AIRBAG SENSOR ASSEMBLY
Dtc B1865/65 Short In Front Passenger Side Knee Airbag Squib Circuit. SUPPLEMENTAL RESTRAINT SYSTEM. Lexus IS250 IS220d GSE20 ALE20

Connect the connectors to the front passenger side knee airbag assembly 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 B1865, B1866, B1867, B1868 or 65 is not output.
  • HINT:
  • Codes other than DTC B1865, B1866, B1867, B1868 and 65 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