Toyota Tundra Service Manual: Seat Belt Buckle Switch (LH) (B1656)

DESCRIPTION

The seat belt buckle switch LH circuit consists of the airbag sensor assembly and front seat inner belt assembly LH (seat belt buckle switch LH).

DTC B1656 is stored when a malfunction is detected in the seat belt buckle switch LH circuit.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

• After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

  Click here

• When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected.

  Click here

PROCEDURE

(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 airbag sensor assembly and front seat inner belt assembly LH.

OK:

Connectors are properly connected.

NG

CONNECT CONNECTORS PROPERLY

OK

(a) Disconnect the connectors from the airbag sensor assembly and front seat inner belt assembly LH.

*1 Front Seat Inner Belt Assembly LH *2 Airbag Sensor Assembly *3 Floor Wire

(b) Check that the connectors (on the airbag sensor assembly side and front seat inner belt assembly LH side) are not damaged.

OK:

Connectors are not deformed or damaged.

NG

REPLACE FLOOR WIRE

OK

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

*1 Front Seat Inner Belt Assembly LH *2 Airbag Sensor Assembly *3 Floor Wire *4 Service Wire *a Front view of wire harness connector (to Front Seat Inner Belt Assembly LH) *b Front view of wire harness connector (to Airbag Sensor Assembly)

(b) Turn the ignition switch to ON.

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

Standard Voltage:

(d) Turn the ignition switch off.

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

(f) Using a service wire, connect terminals 28 (LBE+) and 27 (LBE-) of connector B.

NOTICE:

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

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

Standard Resistance:

(h) Disconnect the service wire from connector B.

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

Standard Resistance:

NG

REPLACE FLOOR WIRE

OK

(a) Connect the connectors to the airbag sensor assembly and front seat inner belt assembly LH.

*1 Front Seat Inner Belt Assembly LH *2 Airbag Sensor Assembly

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

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

(d) Clear the DTCs.

Click here

(e) Turn the ignition switch off.

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

(g) Check for DTCs.

Click here

HINT:

Codes other than DTC B1656 may be output at this time, but they are not related to this check.

B

USE SIMULATION METHOD TO CHECK

A

(a) Turn the ignition switch off.

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

(c) Replace the front seat inner belt assembly LH.

for Center Seat Type:

Click here

except Center Seat:

Click here

HINT:

Perform the inspection using parts from a normal vehicle if possible.

NEXT

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

*1 Front Seat Inner Belt Assembly LH *2 Airbag Sensor Assembly

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

(c) Clear the DTCs.

Click here

(d) Turn the ignition switch off.

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

(f) Check for DTCs.

Click here

HINT:

Codes other than DTC B1656 may be output at this time, but they are not related to this check.

A

END (FRONT SEAT INNER BELT ASSEMBLY LH WAS DEFECTIVE)

B

REPLACE AIRBAG SENSOR ASSEMBLY