Toyota Venza: Seat Position Airbag Sensor Circuit Malfunction (B1653/35)

Toyota Venza Service Manual / Supplemental Restraint Systems / Airbag System / Seat Position Airbag Sensor Circuit Malfunction (B1653/35)

DESCRIPTION

The seat position airbag sensor circuit consists of the center airbag sensor assembly and seat position airbag sensor.

DTC B1653/35 is stored when a malfunction is detected in the seat position airbag sensor circuit.

DTC No.	DTC Detection Condition	Trouble Area
B1653/35	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 seat position airbag sensor circuit. Front seat inner belt assembly LH malfunction Seat position airbag sensor malfunction Center airbag sensor assembly malfunction	Floor wire Front seat inner belt assembly LH Seat position airbag sensor 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, front seat inner belt assembly LH and seat position airbag sensor.

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, front seat inner belt assembly LH and seat position airbag sensor.

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

OK:

The terminals are not deformed or damaged.

REPLACE WIRE HARNESS

2.	CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (OPEN)

(a) Connect the connectors to the front seat inner belt assembly LH and floor wire.

(b) Using SST, connect terminals 9 (LSP+) and 17 (LSP-) of connector B.

NOTICE:

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

SST: 09843-18040

Standard Resistance:

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

Text in Illustration

Seat Position Airbag Sensor

Center Airbag Sensor Assembly

Front view of wire harness connector

(to Center Airbag Sensor Assembly)

Front view of wire harness connector

(to Seat Position Airbag Sensor)

Connector B

Connector E

GO TO STEP 9

3.	CHECK SEAT POSITION AIRBAG SENSOR 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
2 (LSP+) - 1 (LSP-)	Always	1 MΩ or higher

Text in Illustration

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

GO TO STEP 10

4.	CHECK SEAT POSITION AIRBAG SENSOR 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
2 (LSP+) - Body ground	Ignition switch ON	Below 1 V
1 (LSP-) - Body ground	Ignition switch ON	Below 1 V

Text in Illustration

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

GO TO STEP 11

5.	CHECK SEAT POSITION AIRBAG SENSOR 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
2 (LSP+) - Body ground	Always	1 MΩ or higher
1 (LSP-) - Body ground	Always	1 MΩ or higher

Text in Illustration

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

GO TO STEP 12

6.	CHECK SEAT POSITION AIRBAG SENSOR

(a) Connect the connectors to the center airbag sensor assembly and seat position airbag sensor.

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

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

OK:

DTC B1653/35 is not output.

Text in Illustration

*1	Seat Position Airbag Sensor
*2	Center Airbag Sensor Assembly

HINT:

Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.

USE SIMULATION METHOD TO CHECK

7.	REPLACE SEAT POSITION AIRBAG SENSOR

(a) Turn the ignition switch off.

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

HINT:

Perform the following inspection using known good parts from another vehicle if possible.

8.	CHECK CENTER AIRBAG SENSOR ASSEMBLY

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

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

(d) Turn the ignition switch off.

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

(f) Check for DTCs (See page ).

OK:

DTC B1653/35 is not output.

Text in Illustration

*1	Seat Position Airbag Sensor
*2	Center Airbag Sensor Assembly

HINT:

Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.

END

REPLACE CENTER AIRBAG SENSOR ASSEMBLY

9.	CHECK FLOOR WIRE (OPEN)

(a) Disconnect the floor wire from the front seat inner belt assembly LH.

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
L19-2 (LSP+) - L19-4 (LSP-)	Always	Below 1 Ω

Text in Illustration

*1	Seat Position Airbag Sensor	*2	Center Airbag Sensor Assembly
*3	Front Seat Inner Belt Assembly LH	*4	Floor Wire
*5	Front view of wire harness connector (to Center Airbag Sensor Assembly)	*6	Front view of wire harness connector (to Front Seat Inner Belt Assembly LH)
*7	Connector B	*8	Connector C

REPLACE FRONT SEAT INNER BELT ASSEMBLY LH

REPLACE FLOOR WIRE

10.	CHECK FLOOR WIRE (SHORT)

(a) Disconnect the floor wire from the front seat inner belt assembly LH.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
L19-2 (LSP+) - L19-4 (LSP-)	Always	1 MΩ or higher

Text in Illustration

*1	Seat Position Airbag Sensor
*2	Center Airbag Sensor Assembly
*3	Front Seat Inner Belt Assembly LH
*4	Floor Wire
*5	Front view of wire harness connector (to Front Seat Inner Belt Assembly LH)
*6	Connector C

REPLACE FRONT SEAT INNER BELT ASSEMBLY LH

REPLACE FLOOR WIRE

11.	CHECK FLOOR 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
L19-2 (LSP+) - Body ground	Ignition switch ON	Below 1 V
L19-4 (LSP-) - Body ground	Ignition switch ON	Below 1 V

Text in Illustration

*1	Seat Position Airbag Sensor
*2	Center Airbag Sensor Assembly
*3	Front Seat Inner Belt Assembly LH
*4	Floor Wire
*5	Front view of wire harness connector (to Front Seat Inner Belt Assembly LH)
*6	Connector C

REPLACE FRONT SEAT INNER BELT ASSEMBLY LH

REPLACE FLOOR WIRE

12.	CHECK FLOOR WIRE (SHORT TO GROUND)

(a) Disconnect the floor wire from the front seat inner belt assembly LH.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
L19-2 (LSP+) - Body ground	Always	1 MΩ or higher
L19-4 (LSP-) - Body ground	Always	1 MΩ or higher

Text in Illustration

*1	Seat Position Airbag Sensor
*2	Center Airbag Sensor Assembly
*3	Front Seat Inner Belt Assembly LH
*4	Floor Wire
*5	Front view of wire harness connector (to Front Seat Inner Belt Assembly LH)
*6	Connector C

REPLACE FRONT SEAT INNER BELT ASSEMBLY LH

REPLACE FLOOR WIRE

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