Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Seat Belt Buckle Switch (LH) (B1656)

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Vehicle Interior / Supplemental Restraint Systems / Airbag System(for Gasoline Model) / Seat Belt Buckle Switch (LH) (B1656)

DESCRIPTION

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

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

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Test Mode / Check Mode

B1656

Seat Belt Buckle Switch (LH)
  • The airbag ECU assembly detects a line short, short to ground or B+, or an open in the front seat belt buckle switch LH circuit.
  • Front seat belt buckle switch LH malfunction
  • Airbag ECU assembly malfunction
  • Floor wire
  • Front seat belt buckle switch LH (Front seat inner belt assembly LH)
  • Airbag ECU assembly

Comes on

Does not apply to test/check mode

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

After turning the engine 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

PROCEDURE

1.

CHECK CONNECTION OF CONNECTORS

(a) Turn the engine switch off.

(b) Disconnect the cable from the negative (-) battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

(c) Check that the connectors are properly connected to the airbag ECU assembly and front seat inner belt assembly LH.

OK:

The connectors are properly connected.

NG

CONNECT CONNECTORS PROPERLY
OK

2.

CHECK CONNECTORS

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

(b) Check that the terminals of the connectors are not deformed or damaged.

OK:

The terminals are not deformed or damaged.

NG

REPLACE FLOOR WIRE OR FRONT SEAT INNER BELT ASSEMBLY LH
OK

3.

CHECK FLOOR WIRE

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

*A

w/o Seat Position Memory System

*B

w/ Seat Position Memory System

*1

Front Seat Inner Belt Assembly LH

*2

Airbag ECU Assembly

*3

Floor Wire

*4

Service Wire

*a

Front view of wire harness connector

(to Airbag ECU Assembly)

*b

Front view of wire harness connector

(to Front Seat Inner Belt Assembly LH)

(b) Turn the engine switch on (IG).

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

Standard Voltage:

w/o Seat Position Memory System:

Tester Connection

Condition

Specified Condition

K53-2 (LBE+) - Body ground

Engine switch on (IG)

Below 1 V

K53-1 (LBE-) - Body ground

Engine switch on (IG)

Below 1 V
w/ Seat Position Memory System:

Tester Connection

Condition

Specified Condition

K54-1 (LBE+) - Body ground

Engine switch on (IG)

Below 1 V

K54-2 (LBE-) - Body ground

Engine switch on (IG)

Below 1 V

(d) Turn the engine switch off.

(e) Disconnect the cable from the negative (-) battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

(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 the wire.

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

Standard Resistance:

w/o Seat Position Memory System:

Tester Connection

Condition

Specified Condition

K53-2 (LBE+) - K53-1 (LBE-)

Always

Below 1 Ω
w/ Seat Position Memory System:

Tester Connection

Condition

Specified Condition

K54-1 (LBE+) - K54-2 (LBE-)

Always

Below 1 Ω

(h) Disconnect the service wire from connector B.

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

Standard Resistance:

w/o Seat Position Memory System:

Tester Connection

Condition

Specified Condition

K53-2 (LBE+) - K53-1 (LBE-)

Always

1 MΩ or higher

K53-2 (LBE+) - Body ground

Always

1 MΩ or higher

K53-1 (LBE-) - Body ground

Always

1 MΩ or higher
w/ Seat Position Memory System:

Tester Connection

Condition

Specified Condition

K54-1 (LBE+) - K54-2 (LBE-)

Always

1 MΩ or higher

K54-1 (LBE+) - Body ground

Always

1 MΩ or higher

K54-2 (LBE-) - Body ground

Always

1 MΩ or higher
NG

REPLACE FLOOR WIRE
OK

4.

CHECK DTC

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

*1

Front Seat Inner Belt Assembly LH

*2

Airbag ECU Assembly

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

(c) Turn the engine switch on (IG), and wait for at least 60 seconds.

(d) Clear the DTCs stored in memory.

Body Electrical > SRS Airbag > Clear DTCs

(e) Turn the engine switch off.

(f) Turn the engine switch on (IG), and wait for at least 60 seconds.

(g) Check for DTCs.

Body Electrical > SRS Airbag > Trouble Codes

OK:

DTC B1656 is not output.

HINT:

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

OK

USE SIMULATION METHOD TO CHECK

NG

5.

CHECK FRONT SEAT INNER BELT ASSEMBLY LH

(a) Turn the engine switch off.

*1

Front Seat Inner Belt Assembly LH

*2

Airbag ECU Assembly

(b) Disconnect the cable from the negative (-) battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

(c) Replace the front seat inner belt assembly LH with a known good one.

Click here

HINT:

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

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

(e) Turn the engine switch on (IG), and wait for at least 60 seconds.

(f) Clear the DTCs stored in memory.

Body Electrical > SRS Airbag > Clear DTCs

(g) Turn the engine switch off.

(h) Turn the engine switch on (IG), and wait for at least 60 seconds.

(i) Check for DTCs.

Body Electrical > SRS Airbag > Trouble Codes

OK:

DTC B1656 is not output.

HINT:

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

(j) Turn the engine switch off.

(k) Disconnect the cable from the negative (-) battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

(l) Restore the front seat inner belt assembly LH that was installed for testing to its original location.

Click here

OK

REPLACE FRONT SEAT INNER BELT ASSEMBLY LH

NG

REPLACE AIRBAG ECU ASSEMBLY

    Driver Side Seat Position Sensor (B1653)

    P Seat Airbag Active Mode Indicator (B1660)

    See More:

    Toyota Avalon (XX50) 2019-2022 Service & Repair Manual > Power Mirror Control System(for Gasoline Model With Memory): Dtc Check / Clear
    DTC CHECK / CLEAR CHECK DTC (a) Connect the Techstream to the DLC3. (b) Turn the engine switch on (IG). (c) Turn the Techstream on. (d) Enter the following menus: Body Electrical / Mirror L or Mirror R / Trouble Codes. Body Electrical > Mirror L > Trouble Codes Body Electrical > Mirror R &g ...

    Toyota Avalon (XX50) 2019-2022 Owners Manual

    Toyota Avalon (XX50) 2019-2022 Service & Repair Manual

    © 2024 Copyright www.tavalon.net
    0.024