Lexus IS250 IS220d GSE20 ALE20 - SUPPLEMENTAL RESTRAINT SYSTEM
CHECK DRIVER SIDE KNEE AIRBAG ASSEMBLY (DRIVER SIDE KNEE AIRBAG SQUIB)
CHECK INSTRUMENT PANEL WIRE (DRIVER SIDE KNEE AIRBAG SQUIB CIRCUIT)
CHECK CENTER AIRBAG SENSOR ASSEMBLY
DTC B1860/64 Short in Driver Side Knee Airbag Squib Circuit
DTC B1861/64 Open in Driver Side Knee Airbag Squib Circuit
DTC B1862/64 Short to GND in Driver Side Knee Airbag Squib Circuit
DTC B1863/64 Short to B+ in Driver Side Knee Airbag Squib Circuit
DESCRIPTION
The driver side knee airbag squib circuit consists of the center airbag sensor assembly and the driver side knee airbag assembly.
This circuit instructs the SRS to deploy when deployment conditions are met.
These DTCs are recorded when a malfunction is detected in the driver side knee airbag squib circuit.
| DTC No. | DTC Detecting Condition | Trouble Area |
| B1860/64 | The center airbag sensor assembly receives a line short circuit signal 5 times in the driver side knee airbag squib circuit during primary check. Driver side knee airbag squib malfunction Center airbag sensor assembly malfunction | Instrument panel wire Driver side knee airbag assembly (Driver side knee airbag squib) Center airbag sensor assembly |
| B1861/64 | The center airbag sensor assembly receives an open circuit signal in the driver side knee airbag squib circuit for 2 seconds. Driver side knee airbag squib malfunction Center airbag sensor assembly malfunction | Instrument panel wire Driver side knee airbag assembly (Driver side knee airbag squib) Center airbag sensor assembly |
| B1862/64 | The airbag sensor assembly center receives a short circuit to ground signal in the driver side knee airbag squib circuit for 0.5 seconds. Driver side knee airbag squib malfunction Center airbag sensor assembly malfunction | Instrument panel wire Driver side knee airbag assembly (Driver side knee airbag squib) Center airbag sensor assembly |
| B1863/64 | The airbag sensor assembly center receives a short circuit to B+ signal in the driver side knee airbag squib circuit for 0.5 seconds. Driver side knee airbag squib malfunction Center airbag sensor assembly malfunction | Instrument panel wire Driver side knee airbag assembly (Driver side knee airbag squib) Center airbag sensor assembly |
WIRING DIAGRAM
INSPECTION PROCEDURE
- HINT:
| 1.CHECK DRIVER SIDE KNEE AIRBAG ASSEMBLY (DRIVER SIDE KNEE AIRBAG SQUIB) |
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 driver side knee airbag assembly.
Connect the white wire side of SST (resistance 2.1 Ω) to the floor wire.
- CAUTION:
- Never connect a tester to the driver side knee airbag assembly (driver side knee airbag squib) for measurement, as this may lead to a serious injury due to airbag deployment.
- NOTICE:
- 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 B1860, B1861, B1862, B1863 or 64 is not output.
- HINT:
- Codes other than DTC B1860, B1861, B1862, B1863 and 64 may be output at this time, but they are not related to this check.
|
| ||||
| 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 driver 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.
|
| ||||
| OK | |
| 3.CHECK INSTRUMENT PANEL WIRE (DRIVER SIDE KNEE AIRBAG SQUIB CIRCUIT) |
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 connection Condition Specified condition J20-1 (DK+) - Body ground Engine switch on (IG) Below 1 V J20-2 (DK-) - Body ground Engine 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 connection Condition Specified condition J20-1 (DK+) - J20-2 (DK-) Always Below 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 connection Condition Specified condition J20-1 (DK+) - Body ground Always 1 MΩ or higher J20-2 (DK-) - Body ground Always 1 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 connection Condition Specified condition J20-1 (DK+) - J20-2 (DK-) Always 1 MΩ or higher
|
| ||||
| OK | |
| 4.CHECK CENTER AIRBAG SENSOR ASSEMBLY |
Connect the connectors to the driver 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 stored DTCs 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 B1860, B1861, B1862, B1863 or 64 is not output.
- HINT:
- Codes other than DTC B1860, B1861, B1862, B1863 and 64 may be output at this time, but they are not related to this check.
|
| ||||
| OK | ||
| ||