Toyota Venza: Lost Communication with Front Airbag Sensor LH (B1617/84,B1618/84)

Toyota Venza Service Manual / Supplemental Restraint Systems / Airbag System / Lost Communication with Front Airbag Sensor LH (B1617/84,B1618/84)

DESCRIPTION

The front airbag sensor LH circuit consists of the center airbag sensor assembly and front airbag sensor LH.

The front airbag sensor LH detects impacts to the vehicle and sends signals to the center airbag sensor assembly to determine if the airbag should be deployed.

These DTCs are stored when a malfunction is detected in the front airbag sensor LH circuit.

DTC No.	DTC Detection Condition	Trouble Area
B1617/84 B1618/84	The center airbag sensor assembly receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the front airbag sensor LH circuit. Front airbag sensor LH malfunction Center airbag sensor assembly malfunction	Instrument panel wire Engine room main wire Front airbag sensor LH Center airbag sensor assembly

DTC No.

DTC Detection Condition

Trouble Area

B1617/84

B1618/84

The center airbag sensor assembly receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the front airbag sensor LH circuit.
Front airbag sensor LH malfunction
Center airbag sensor assembly malfunction

Instrument panel wire
Engine room main wire
Front airbag sensor LH
Center airbag sensor assembly

WIRING DIAGRAM

PROCEDURE

1.	CHECK CONNECTORS

(a) Turn the ignition switch off.

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

(c) Check that the connectors are properly connected to the center airbag sensor assembly and front airbag sensor LH. Also check that the connectors that link the engine room main wire and instrument panel wire are properly connected.

OK:

The connectors are properly connected.

HINT:

If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

(d) Disconnect the connectors from the center airbag sensor assembly and front airbag sensor LH. Also disconnect the connectors that link the engine room main wire and instrument panel wire.

(e) Check that the terminals of connectors are not damaged.

OK:

The terminals are not deformed or damaged.

REPLACE WIRE HARNESS

2.	CHECK FRONT AIRBAG SENSOR LH CIRCUIT (OPEN)

(a) Connect the connectors that link the engine room main wire and instrument panel wire.

(b) Using SST, connect terminals 30 (+SL) and 28 (-SL) of connector B.

NOTICE:

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

SST: 09843-18040

Standard Resistance:

Tester Connection	Condition	Specified Condition
A25-2 (+SL) - A25-1 (-SL)	Always	Below 1 Ω

Text in Illustration

Front Airbag Sensor LH

Center Airbag Sensor Assembly

Front view of wire harness connector

(to Center Airbag Sensor Assembly)

Front view of wire harness connector

(to Front Airbag Sensor LH)

Connector B

Connector E

GO TO STEP 7

3.	CHECK FRONT AIRBAG SENSOR LH CIRCUIT (SHORT)

(a) Disconnect SST from connector B.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A25-2 (+SL) - A25-1 (-SL)	Always	1 MΩ or higher

Text in Illustration

*1	Front Airbag Sensor LH
*2	Center Airbag Sensor Assembly
*3	Front view of wire harness connector (to Front Airbag Sensor LH)
*4	Connector E

GO TO STEP 8

4.	CHECK FRONT AIRBAG SENSOR LH CIRCUIT (SHORT TO B+)

(a) Connect the cable to the negative (-) battery terminal.

(b) Turn the ignition switch to ON.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A25-2 (+SL) - Body ground	Ignition switch ON	Below 1 V
A25-1 (-SL) - Body ground	Ignition switch ON	Below 1 V

Text in Illustration

*1	Front Airbag Sensor LH
*2	Center Airbag Sensor Assembly
*3	Front view of wire harness connector (to Front Airbag Sensor LH)
*4	Connector E

GO TO STEP 9

5.	CHECK FRONT AIRBAG SENSOR LH CIRCUIT (SHORT TO GROUND)

(a) Turn the ignition switch off.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A25-2 (+SL) - Body ground	Always	1 MΩ or higher
A25-1 (-SL) - Body ground	Always	1 MΩ or higher

Text in Illustration

*1	Front Airbag Sensor LH
*2	Center Airbag Sensor Assembly
*3	Front view of wire harness connector (to Front Airbag Sensor LH)
*4	Connector E

GO TO STEP 10

6.	CHECK FRONT AIRBAG SENSOR LH

(a) Connect the connector to the center airbag sensor assembly.

(b) Interchange the front airbag sensor RH with LH and connect the connectors.

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

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

Result	Proceed to
DTCs B1612/83, B1613/83, B1617/84 and B1618/84 are not output.	A
DTC B1617/84 or B1618/84 is output.	B
DTC B1612/83 or B1613/83 is output.	C

Text in Illustration

*1	Front Airbag Sensor RH
*2	Center Airbag Sensor Assembly

HINT:

Codes other than DTCs B1612/83, B1613/83, B1617/84 and B1618/84 may be output at this time, but they are not related to this check.

USE SIMULATION METHOD TO CHECK

REPLACE CENTER AIRBAG SENSOR ASSEMBLY

REPLACE FRONT AIRBAG SENSOR LH

7.	CHECK INSTRUMENT PANEL WIRE (OPEN)

(a) Disconnect the instrument panel wire connector from the engine room main wire.

HINT:

SST has already been inserted into connector B.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
DA4-4 (+SL) - DA4-3 (-SL)	Always	Below 1 Ω

Text in Illustration

*1	Front Airbag Sensor LH	*2	Center Airbag Sensor Assembly
*3	Engine Room Main Wire	*4	Instrument Panel Wire
*5	Front view of wire harness connector (to Center Airbag Sensor Assembly)	*6	Front view of wire harness connector (to Engine Room Main Wire)
*7	Connector B	*8	Connector C

REPLACE ENGINE ROOM MAIN WIRE

REPLACE INSTRUMENT PANEL WIRE

8.	CHECK INSTRUMENT PANEL WIRE (SHORT)

(a) Disconnect the instrument panel wire connector from the engine room main wire.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
DA4-4 (+SL) - DA4-3 (-SL)	Always	1 MΩ or higher

Text in Illustration

*1	Front Airbag Sensor LH
*2	Center Airbag Sensor Assembly
*3	Engine Room Main Wire
*4	Instrument Panel Wire
*5	Front view of wire harness connector (to Engine Room Main Wire)
*6	Connector C

REPLACE ENGINE ROOM MAIN WIRE

REPLACE INSTRUMENT PANEL WIRE

9.	CHECK INSTRUMENT PANEL WIRE (SHORT TO B+)

(a) Turn the ignition switch off.

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

(d) Connect the cable to the negative (-) battery terminal.

(e) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
DA4-4 (+SL) - Body ground	Ignition switch ON	Below 1 V
DA4-3 (-SL) - Body ground	Ignition switch ON	Below 1 V

Text in Illustration

*1	Front Airbag Sensor LH
*2	Center Airbag Sensor Assembly
*3	Engine Room Main Wire
*4	Instrument Panel Wire
*5	Front view of wire harness connector (to Engine Room Main Wire)
*6	Connector C

REPLACE ENGINE ROOM MAIN WIRE

REPLACE INSTRUMENT PANEL WIRE

10.	CHECK INSTRUMENT PANEL WIRE (SHORT TO GROUND)

(a) Disconnect the instrument panel wire connector from the engine room main wire.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
DA4-4 (+SL) - Body ground	Always	1 MΩ or higher
DA4-3 (-SL) - Body ground	Always	1 MΩ or higher

Text in Illustration

*1	Front Airbag Sensor LH
*2	Center Airbag Sensor Assembly
*3	Engine Room Main Wire
*4	Instrument Panel Wire
*5	Front view of wire harness connector (to Engine Room Main Wire)
*6	Connector C

REPLACE ENGINE ROOM MAIN WIRE

REPLACE INSTRUMENT PANEL WIRE

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