SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B1860/64-B1863/64; Short in Driver Side Knee Airbag Squib Circuit; 2016 - 2020 MY Sienna [12/2015

Last Modified: 04-05-2023	6.11:8.1.0	Doc ID: RM100000000VJQZ
Model Year Start: 2016	Model: Sienna	Prod Date Range: [12/2015 - ]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B1860/64-B1863/64; Short in Driver Side Knee Airbag Squib Circuit; 2016 - 2020 MY Sienna [12/2015 - ]

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 knee airbag squib circuit consists of the center airbag sensor assembly and the knee airbag assembly.

This circuit signals the SRS to deploy when deployment conditions are met.

These DTCs are recorded when a malfunction is detected in the knee airbag squib circuit.

DTC No.	DTC Detection Condition	Trouble Area
B1860/64	Center airbag sensor assembly detects line short circuit signal 5 times in knee airbag squib circuit during primary check. Knee airbag squib malfunction Center airbag sensor assembly malfunction	Instrument panel wire Knee airbag assembly (Knee airbag squib) Center airbag sensor assembly
B1861/64	Center airbag sensor assembly detects open circuit signal in knee airbag squib circuit for 2 seconds. Knee airbag squib malfunction Center airbag sensor assembly malfunction	Instrument panel wire Knee airbag assembly (Knee airbag squib) Center airbag sensor assembly
B1862/64	Center airbag sensor assembly detects short circuit to ground signal in knee airbag squib circuit for 0.5 seconds. Knee airbag squib malfunction Center airbag sensor assembly malfunction	Instrument panel wire Knee airbag assembly (Knee airbag squib) Center airbag sensor assembly
B1863/64	Center airbag sensor assembly detects short circuit to B+ signal in knee airbag squib circuit for 0.5 seconds. Knee airbag squib malfunction Center airbag sensor assembly malfunction	Instrument panel wire Knee airbag assembly (Knee airbag squib) Center airbag sensor assembly

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

Perform the simulation method by selecting CHECK MODE (signal check) with the Techstream (See page ).
After selecting 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 (See page ).

PROCEDURE

1.	CHECK CONNECTOR

(a) Turn the ignition switch off.

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

OK:

The connector is properly connected.

HINT:

If the connector is not connected securely, reconnect the connector and proceed to the next inspection.

(d) Disconnect the connector from the knee airbag assembly.

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

OK:

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

REPLACE INSTRUMENT PANEL WIRE

2.	CHECK KNEE AIRBAG ASSEMBLY (KNEE AIRBAG SQUIB)

SST: 09843-18061

(a) Connect SST (resistance 2.1 Ω) to connector C.

CAUTION:

Never connect a tester to the knee airbag assembly (knee airbag squib) for measurement, as this may lead to a serious injury due to airbag deployment.

NOTICE:

Do not forcibly insert SST into the terminals of the connector when connecting.
Insert SST straight into the terminals of the connector.

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

(d) Clear the DTCs stored in the memory (See page ).

(e) Turn the ignition switch off.

(f) Turn the ignition switch to ON, and wait for at least 60 seconds.

(g) Check the DTCs (See page ).

OK:

DTC B1860/64, B1861/64, B1862/64 or B1863/64 is not output.

Text in Illustration

*1	Knee Airbag Squib
*2	Center Airbag Sensor Assembly
*3	Connector C
*a	Front view of wire harness connector (to Knee Airbag Squib)

HINT:

DTCs other than B1860/64, B1861/64, B1862/64 and B1863/64 may be output at this time, but they are not related to this check.

REPLACE KNEE AIRBAG ASSEMBLY

3.	CHECK CONNECTOR

(a) Turn the ignition switch off.

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

(d) Check that the connector is properly connected to the center airbag sensor assembly.

OK:

The connector is properly connected.

HINT:

If the connector is not connected securely, reconnect the connector and proceed to the next inspection.

(e) Disconnect the connector from the center airbag sensor assembly.

(f) Check that the terminal of the connector is not damaged.

OK:

The terminal is not deformed or damaged.

(g) Check that the short spring for the instrument panel wire connector with the activation prevention mechanism is not deformed or damaged.

OK:

The short spring is not deformed or damaged.

REPLACE INSTRUMENT PANEL WIRE

4.	CHECK INSTRUMENT PANEL WIRE (KNEE AIRBAG SQUIB - CENTER AIRBAG SENSOR ASSEMBLY)

(a) Disconnect the connectors from the center airbag sensor assembly.

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

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
D15-1 (DK+) - Body ground	Ignition switch ON	Below 1 V
D15-2 (DK-) - Body ground	Ignition switch ON	Below 1 V

Text in Illustration

*1	Knee Airbag Squib
*2	Instrument Panel Wire
*3	Center Airbag Sensor Assembly
*4	Connector C
*a	Front view of wire harness connector (to Knee Airbag Squib)

(e) Turn the ignition switch off.

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
D15-1 (DK+) - D15-2 (DK-)	Always	Below 1 Ω

(h) Release the activation prevention mechanism built into connector B (See page ).

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
D15-1 (DK+) - D15-2 (DK-)	Always	1 MΩ or higher
D15-1 (DK+) - Body ground	Always	1 MΩ or higher
D15-2 (DK-) - Body ground	Always	1 MΩ or higher

REPLACE INSTRUMENT PANEL WIRE

5.	CHECK CENTER AIRBAG SENSOR ASSEMBLY

(a) Restore the released activation prevention mechanism of connector B to the original condition.

(b) Connect the connectors to the knee airbag assembly and the center airbag sensor assembly.

(d) Turn the ignition switch to ON, and wait for at least 60 seconds.

(e) Clear the DTCs stored in the memory (See page ).

(f) Turn the ignition switch off.

(g) Turn the ignition switch to ON, and wait for at least 60 seconds.

(h) Check the DTCs (See page ).

OK:

DTC B1860/64, B1861/64, B1862/64 or B1863/64 is not output.

Text in Illustration

*1	Knee Airbag Squib
*2	Center Airbag Sensor Assembly

HINT:

DTCs other than B1860/64, B1861/64, B1862/64 and B1863/64 may be output at this time, but they are not related to this check.

USE SIMULATION METHOD TO CHECK

REPLACE CENTER AIRBAG SENSOR ASSEMBLY